CN219306393U - Foldable baby crib - Google Patents

Abstract

The utility model relates to a foldable baby crib, which comprises a side fence and a bottom frame, wherein the side fence comprises a foldable cross rod, the foldable cross rod comprises a first locking mechanism and a movable unlocking piece, the movable unlocking piece is provided with a first unlocking stroke for unlocking the first locking mechanism, the bottom frame comprises a lifting turnover mechanism, the lifting turnover mechanism comprises a second locking mechanism and a lifting handle, the lifting handle is provided with a second unlocking stroke for unlocking the second locking mechanism, the foldable baby crib further comprises a first linkage structure, the lifting handle is in linkage connection with the movable unlocking piece through the first linkage structure, so that the second unlocking stroke of the lifting handle can trigger the first unlocking stroke of the movable unlocking piece, and the foldable baby crib further comprises a second linkage structure, and the second linkage structure is used for linking the foldable cross rod to be unfolded when the bottom frame is unfolded.

Description

Foldable baby crib

Technical Field

The utility model relates to the technical field of crib manufacturing, in particular to a foldable crib capable of being folded or unfolded in one step.

Background

Crib is a common equipment in the infant care field. One conventional playpen framework structure is shown in fig. 1, in which a playpen framework portion includes a base frame 200 and a side rail 100, the base frame 200 serving as a bottom support, and the side rail 100 includes a vertical bar 102 vertically connected to the base frame 200 and a foldable cross bar 101 connected between the vertical bar 102 and the vertical bar 102 to form a closed rail structure. The foldable crib is widely adopted because of the characteristics of easy folding, easy transportation and small occupied space, the foldable crib is provided with a folding structure for the underframe 200 and the side fence 100 to be unfolded and folded conveniently, the underframe 200 is widely adopted to be provided with a lifting turnover structure 201 with a handle, when the handle is lifted, the underframe rod 202 of the underframe 200 is turned up and folded relatively, and simultaneously, all the vertical rods 102 of the side fence 100 are pulled to be close to each other; the side rail 100 is widely used with a folding joint 103 on the foldable rail 101, and the folding joint 103 enables the foldable rail 101 to be folded in half, which is a common technology in the art.

In order to prevent the crib from collapsing, a locking structure is required for both the folding joint 103 and the lifting and folding structure 201, so that the underframe 200 and the side rail 100 are both in a locked unfolded state in the unfolded state of the crib. Thus, the folding of the existing foldable crib is achieved by: when the crib is in an unfolding state, the locking structure of the folding joint 103 is manually operated to unlock the folding joint 103, and at the moment, the foldable cross rod 101 is changed from a horizontal locking state to a loose unlocking state which is concavely bent downwards under the influence of gravity; then, the locking structure of the lifting turnover structure 201 is manually operated, so that the lifting turnover structure 201 is unlocked, the handle of the lifting turnover structure 201 is pulled upwards, the bottom rack bar 202 is turned and erected, the bottom rack bar 202 pulls the vertical bars 102 to be close to each other, and the foldable cross bar 101 between the vertical bars 102 and the vertical bars 102 is folded upwards, so that the folding process is completed. The unfolding process of the foldable crib is as follows: when the crib is in a folded state, the folding structure 201 is manually pushed down to unfold the bottom frame rod 202, the vertical rods 102 and the foldable cross rod 101, but at this time, the foldable cross rod 101 is still in a loose unlocking state, so that the foldable cross rod 101 must be straightened by manually pulling the folding joint 103 upwards, so that the foldable cross rod 101 and the folding joint 103 enter a locking state, and the unfolding process of the crib can be finally completed.

In summary, since the folding joint 103 and the lifting folding structure 201 of the crib in the prior art are independent of each other and have no linkage relationship, no matter the crib is folded or unfolded, at least two steps of operations (respectively operating the lifting folding structure 201 and the folding joint 103) are required to be performed on the crib, and the folding and the unfolding cannot be realized in one step, so that the operation is slightly complicated.

Disclosure of Invention

Therefore, in view of the above problems, the present utility model provides a foldable crib with optimized structure, which can realize one-step folding or unfolding of the crib.

The utility model is realized by adopting the following technical scheme:

the utility model provides a foldable baby crib, which comprises a side fence and a bottom frame, wherein the side fence comprises a foldable cross rod, the foldable cross rod is provided with a first locking mechanism, the first locking mechanism is used for locking the folding action of the foldable cross rod when the foldable baby crib is unfolded, the bottom frame comprises a lifting turnover mechanism, the lifting turnover mechanism is provided with a second locking mechanism, the second locking mechanism is used for locking the folding action of the lifting turnover mechanism when the foldable baby crib is unfolded, the foldable cross rod comprises a movable unlocking piece, the movable unlocking piece is provided with a first unlocking stroke for unlocking the first locking mechanism, the lifting turnover mechanism comprises a lifting handle, the lifting handle is provided with a second unlocking stroke for unlocking the second locking mechanism, and the foldable baby crib further comprises a first linkage structure, and the lifting handle and the movable unlocking piece are in linkage connection through the first linkage structure, so that the second unlocking stroke of the lifting handle can trigger the first unlocking stroke of the movable unlocking piece.

In one embodiment, the side rail further comprises a plurality of vertical rods, the foldable cross rod is arranged between the vertical rods and the vertical rods, two ends of the foldable cross rod are respectively and rotatably connected with one of the vertical rods, the bottom frame further comprises bottom frame rods corresponding to the number of the vertical rods, the inner ends of the plurality of bottom frame rods are assembled and are rotatably connected with the lifting turnover mechanism, and the lower end of each vertical rod is connected with the outer end of one of the bottom frame rods.

In one embodiment, the first linkage structure is a first pull wire, the upper end of the first pull wire is in linkage connection with the movable unlocking piece, and the lower end of the first pull wire is in linkage connection with the handle.

In one embodiment, the second unlocking stroke is a rotation stroke of the lifting handle on the vertical axis, and the first unlocking stroke is a sliding stroke of the movable unlocking piece vertically downwards, so that the lifting handle can pull the movable unlocking piece to slide downwards to perform a first unlocking stroke when rotating the second unlocking stroke.

Wherein, in an embodiment, carry and draw folding mechanism and still include cover seat and handle rolling disc, the cover seat is hollow cover column structure, and including a slide sleeve chamber that the axis vertically extends along upper and lower direction, end hack lever and cover seat rotatable coupling, handle rolling disc rotationally cooperate in the slide sleeve intracavity, handle rolling disc and handle coaxial coupling to make the handle rotate along vertical axis.

In one embodiment, the second locking mechanism comprises a lock pin, a lock pin guide seat and an elastic reset piece, wherein the lock pin guide seat is tightly attached to the lower end of the handle rotating disc, a linear guide groove extending horizontally is arranged on the lock pin guide seat, the lock pin is slidably matched in the linear guide groove, a guide pillar is fixedly arranged at the upper end of the lock pin, an arc guide groove is arranged at the lower end of the handle rotating disc, the outer edge of the arc guide groove is in an arc shape which is gradually bent and close to the radial inner end of the handle rotating disc from the radial outer end of the handle rotating disc, the guide pillar is inserted in the arc guide groove, the first end of the elastic reset piece acts on the lock pin guide seat, the second end of the elastic reset piece acts on the lock pin to enable the lock pin to have a trend of radially outwards moving, and a lock hole for being inserted with the lock pin is arranged on the sleeve seat.

Wherein, in one embodiment, the lower end of the first stay wire is fixedly connected with the handle/handle rotating disc; or, the handle rotating disc comprises a disc body and a connecting shaft fixed on one end face of the disc body, the handle and the disc body are coaxially connected through the connecting shaft, a lifting sleeve is sleeved on the connecting shaft, a first slope is arranged on the disc body, a second slope is arranged on the lifting sleeve, the first slope and the second slope are in collision to form oblique guide fit, so that the lifting sleeve can be jacked up through the oblique guide fit of the first slope and the second slope when the disc body rotates, and the lower end of the first stay wire is fixedly connected with the lifting sleeve.

In one embodiment, the foldable cross rod further comprises a first folding rod, a second folding rod and a folding joint arranged between the first folding rod and the second folding rod, the folding joint comprises a joint base body, the first folding rod and the second folding rod are respectively pivoted at the left end and the right end of the joint base body, the movable unlocking piece is a sliding block which is arranged between the first folding rod and the second folding rod and can slide up and down, and the upper end of the first pull wire is fixedly connected with the sliding block.

In one embodiment, the first locking mechanism comprises a first limiting pin and a second limiting pin, a first transverse groove and a second transverse groove which extend leftwards and rightwards are formed in the joint substrate, the first transverse groove and the second transverse groove are respectively close to the first folding rod and the second folding rod and are bilaterally symmetrical, a first chute and a second chute which extend obliquely and are bilaterally mirror symmetrical are arranged on the sliding block, the first limiting pin is simultaneously in sliding fit in the first transverse groove and the first chute, the second limiting pin is simultaneously in sliding fit in the second transverse groove and the second chute, and accordingly the upper and lower sliding of the sliding block is converted into sliding that the first limiting pin and the second limiting pin are synchronously far away from or close to each other in the left-right direction through the first chute and the second chute, and the first limiting pin and the second limiting pin are used for resisting and locking relative folding of the first folding rod and the second folding rod.

Wherein, in one embodiment, still include second linkage structure, second linkage structure is used for linking collapsible horizontal pole relative deployment when chassis pole is expanded.

Wherein, in an embodiment, collapsible horizontal pole further includes first folding pole, second folding pole and locates the folding joint between first folding pole and the second folding pole, and second linkage includes rotatory linkage and second acting as go-between, and rotatory linkage rotationally sets up the outer end at the end of end hack lever, end and rotatory linkage activity hinge, and its upper end of second acting as go-between to lower extreme along collapsible horizontal pole and montant extension arrangement in proper order, second acting as go-between upper end is connected in first folding pole or second folding pole, lower extreme and rotatory linkage fixed connection to through rotatory linkage pulling second acting as go-between when the end hack lever is expanded, in order to pull first folding pole and second folding pole relative expansion.

In one embodiment, the device further comprises a support fixedly connected to the lower end of the vertical rod, the underframe rod is rotatably connected to the support and can turn over between two vertical and horizontal limit positions relative to the support, the rotary linkage piece is hinged to the support, a first connecting portion and a second connecting portion are respectively arranged at two sides of a hinge point of the rotary linkage piece and the support, the first connecting portion is used for fixing the lower end of the second stay wire, the second connecting portion is a strip-shaped groove, and the outer end of the underframe rod is hinged to the strip-shaped groove.

In one embodiment, the lifting turnover mechanism further comprises a lifting combined core body and a sleeve seat, the sleeve seat is of a hollow sleeve-shaped structure and comprises a sliding sleeve cavity with an axis extending vertically in the up-down direction, the lifting combined core body can be inserted and matched in the sliding sleeve cavity in a up-down sliding mode, a lifting handle is arranged at the top end of the lifting combined core body, racks which correspond to the number of the bottom rack rods and extend in the up-down direction are arranged on the outer periphery side of the lifting combined core body, arc-shaped tooth parts are fixedly connected to the inner ends of the bottom rack rods, windows are arranged on the sleeve seat, the bottom rack rods are connected with the sleeve seat in a rotating mode, and the arc-shaped tooth parts of the bottom rack rods extend into the inner cavities of the sleeve seat from the windows and are meshed with the racks correspondingly.

In one embodiment, the pull combined core body further comprises a straight tooth sleeve, a handle rotating disc, a lock pin guide seat and a lower cover, wherein the handle rotating disc is rotatably matched in the sliding sleeve cavity, the handle rotating disc comprises a disc body and a connecting shaft fixed on one end face of the disc body, the handle and the disc body are coaxially connected through the connecting shaft, the straight tooth sleeve is of a hollow cylindrical structure with two open ends, the connecting shaft penetrates through the straight tooth sleeve, the lock pin guide seat is arranged at the lower end of the handle rotating disc, the lower cover is arranged at the lower end of the lock pin guide seat, the straight tooth sleeve, the lock pin guide seat and the lower cover are fixedly connected through screws, a yielding groove for the screws to penetrate is formed in the handle rotating disc, and the rack is fixedly arranged at the periphery of the straight tooth sleeve.

The utility model has the following beneficial effects: according to the foldable crib, the first linkage structure and the second linkage structure enable the unfolding and folding processes to be achieved only by applying force at one position of the lifting and folding mechanism, and operation of folding joints is not needed. Realizes one-step unfolding or folding of the foldable crib, and greatly simplifies the manual operation of the crib.

Drawings

FIG. 1 is a schematic view of a prior art collapsible crib;

FIG. 2 is a schematic view of a foldable crib deployment in an embodiment;

FIG. 3 is an exploded view of the structure of the foldable crib in an embodiment;

FIG. 4 is a schematic view of a folding joint in an embodiment;

FIG. 5 is an exploded view of the structure of the folding joint in an embodiment;

FIG. 6 is a cross-sectional view of a folding joint in an embodiment;

FIG. 7 is an exploded view of the chassis of the embodiment;

FIG. 8 is an exploded view of the lift and flip mechanism in an embodiment;

FIG. 9 is an exploded view of the structure of the pull-up composite core of the embodiment (angle one);

FIG. 10 is an exploded view of the structure of the pull-up composite core of the embodiment (angle two);

FIG. 11 is a schematic view of the inner end of a chassis rod in an embodiment;

FIG. 12 is a cross-sectional view of the lift and flip mechanism (chassis unfolded) in an embodiment;

FIG. 13 is a cross-sectional view of the lift and fold mechanism (chassis folded) in an embodiment;

FIG. 14 is a schematic view of the bottom bracket bar, the support, the second wire and the rotary linkage in an embodiment;

FIG. 15 is a schematic view of the linkage of the bottom bracket bar and the rotary linkage in an embodiment wherein the bottom bracket bar is in a vertical extreme position;

FIG. 16 is a schematic illustration of the linkage of the undercarriage lever and the rotary linkage in an embodiment wherein the undercarriage lever is in an inclined position between vertical and horizontal;

FIG. 17 is a schematic illustration of the linkage of the bottom bracket bar and the rotary linkage in an embodiment wherein the bottom bracket bar is in a horizontal extreme position;

FIG. 18 is a schematic view of a foldable crib half-fold in an embodiment;

fig. 19 is a schematic view of a foldable crib of an embodiment, substantially fully folded.

Detailed Description

For further illustration of the various embodiments, the utility model is provided with the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments and together with the description, serve to explain the principles of the embodiments. With reference to these matters, one of ordinary skill in the art will understand other possible embodiments and advantages of the present utility model. The components in the figures are not drawn to scale and like reference numerals are generally used to designate like components.

The utility model will now be further described with reference to the drawings and detailed description.

Referring to fig. 2-3, as a preferred embodiment of the present utility model, a foldable crib is provided, comprising a siderail 10 and a base frame 20, the orientation of which is described in this embodiment with respect to the static use orientation of the crib in an unfolded state, i.e., the base frame 20 is in a relatively lower position. The side rail 10 includes a plurality of vertical bars 102 extending up and down, the vertical bars 102 are connected to the bottom frame 20 in a downward standing manner, the foldable cross bar 101 is disposed between every two vertical bars 102, and two ends of the foldable cross bar 101 are respectively connected with one vertical bar 102 in a rotatable manner. The underframe 20 comprises underframe rods 201 corresponding to the number of the vertical rods 102, the inner ends of the plurality of underframe rods 201 are converged and are all rotatably connected to the lifting turnover mechanism 2, and the outer end of each underframe rod 201 is connected with one vertical rod 102 through a support 4.

The foldable cross bar 101 has a structure as shown in fig. 4 to 6, and includes a first folding bar 1011, a second folding bar 1012, and a folding joint 1 provided between the first folding bar 1011 and the second folding bar 1012, the folding joint 1 including a joint base 11, and the first folding bar 1011 and the second folding bar 1012 are pivotally connected to left and right ends of the joint base 11, respectively, so as to be capable of being relatively unfolded or folded. The first folding rod 1011 is further inserted with a limiting bolt 50, the limiting bolt 50 can be slidably matched in an arc-shaped groove 113 arranged on the joint base 11, the rotation range of the first folding rod 1011 is limited by the interference fit of the limiting bolt 50 and two groove ends of the arc-shaped groove 113, and the radian of the arc-shaped groove 113 is ninety degrees, so that the first folding rod 1011 only rotates between two extreme positions in a vertical state (namely a folding state) and a horizontal state (namely an unfolding state). The second folding bar 1012 and the first folding bar 1011 are mirror symmetrical structures, and the connection manner thereof with the joint base 11 is the same, and will not be described again.

The folding joint 1 further comprises a slider 12, a guide holder 13 and a first locking mechanism 1100, the first locking mechanism 1100 being used for simultaneously locking or unlocking the pivoting of the first folding bar 1011 and the second folding bar 1012 with respect to the folding. In this embodiment, the first locking mechanism 1100 includes a first limiting pin 14 and a second limiting pin 15, a first transverse slot 111 and a second transverse slot 112 extending from left to right are disposed on the joint base 11, the first transverse slot 111 and the second transverse slot 112 are respectively close to the first folding bar 1011 and the second folding bar 1012 and are symmetrical from left to right, the guide holder 13 is fixedly connected on the joint base 11, the slide block 12 is slidably connected with the guide holder 13 up and down, a first chute 121 and a second chute 122 extending obliquely and having mirror symmetry from left to right are disposed on the slide block 12, the first limiting pin 14 is simultaneously slidably fitted in the first transverse slot 111 and the first chute 121, the second limiting pin 15 is simultaneously slidably fitted in the second transverse slot 112 and the second chute 122, thus, the up-and-down sliding of the slider 12 is converted into the sliding of the first limiting pin 14 and the second limiting pin 15 that are synchronously separated from or approaching to each other in the left-right direction through the first chute 121 and the second chute 122, when the slider 12 is at the higher position, the first limiting pin 14 and the second limiting pin 15 are relatively separated, the first folding lever 1011 and the second folding lever 1012 overlap the first limiting pin 14 and the second limiting pin 15, respectively, so that the rotation of the first folding lever 1011 and the second folding lever 1012 relative to the folding is blocked and locked by the first limiting pin 14 and the second limiting pin 15 (as shown in fig. 6), and the foldable cross bar 101 can be maintained in the unfolded state. When the slider 12 is at the lower position, the first and second stopper pins 14 and 15 are relatively close, and the first and second folding bars 1011 and 1012 are out of contact with the first and second stopper pins 14 and 15, respectively, so that the pivoting of the first and second folding bars 1011 and 1012 with respect to folding is unlocked.

It should be apparent that the slider 12 may be directly slidably connected to the joint base 11, as long as the slider 12 has a vertical sliding stroke. In this embodiment, the structure of the first chute 121 and the second chute 122 is used to convert the up-down motion of the slider 12 into the left-right motion of the first limiting pin 14 and the second limiting pin 15, which is simple, compact and reliable, and in other embodiments, other linkage structures may be used to lock or unlock the first folding bar 1011 and the second folding bar 1012 by the slider 12, for example, a linkage structure is used to link the first folding bar 1011 (the second folding bar 1012) and the first limiting pin 14 (the second limiting pin 15).

As shown in fig. 6, in this embodiment, a slide way 131 is disposed in the guide seat 13, the sliding block 12 is slidably connected to the slide way 131, meanwhile, the slide way 131 further provides an inner cavity space for installing an elastic restoring member 60, a first end of the elastic restoring member 60 acts on the guide seat 13, a second end of the elastic restoring member 60 acts on the sliding block 12, and is used for restoring the sliding of the sliding block 12, that is, when the sliding block 12 moves downward, the elastic restoring member 60 stores energy, after the downward force applied to the sliding block 12 is removed, the elastic restoring member 60 releases energy to act on the sliding block 12 to restore it upward, and at this time, the first limiting pin 14 and the second limiting pin 15 also restore to a relatively far locking position. The elastic restoring member 60 is a compression spring in this embodiment. The provision of the elastic restoring member 60 in the slideway 131 can improve the compactness of the structure of the folding joint 3. In other embodiments, the elastic restoring member may be disposed between the joint base 11 and the slider 12, but the materials and the installation mode should be changed adaptively, for example, the elastic restoring member is replaced by a pull spring, and the pull spring is connected with the joint base 11 and the slider 12 through a pull hook.

As shown in fig. 5, in order to reliably overlap the first folding lever 1011 and the first stopper pin 14, a sheet-shaped overlap joint 1013 is fixed to an end of the first folding lever 1011 rod body relatively close to the folding joint 1, and the overlap joint 1013 end has a sloped surface 1013A. When the crib is unfolded from the folded state, the inclined guide surface 1013A of the overlap joint 1013 can push the first limit pin 14 to approach the second limit pin 15, so that the first folding bar 1011 can pass over the first limit pin 14 and return to the unfolded state in a horizontal direction. The second folding bar 1012, which is mirror symmetrical to the first folding bar 1011, also has the same lap joint structure.

The above description explains the unlocking mechanism of the locking structure of the folding joint 1 in the present embodiment, that is, the pivoting of locking or unlocking the first folding lever 1011 and the second folding lever 1012 with respect to folding by the up-down sliding of the slider 12. That is, the downward sliding stroke of the slider 12 is the first unlocking stroke of the first locking mechanism 1100. In other embodiments, other movable unlocking members may be used instead of the slider 12, such as a swing unlocking member that controls the movement of the first limiting pin 14 and the second limiting pin 15 through a transmission manner such as a link, or the swing unlocking member and the slider 12 of this embodiment form a swing link slider mechanism, but the solution of using the slider 12 is more beneficial to cooperate with the structure of the first pull wire 32 described below, so that the pulling driving force of the first pull wire 32 is more directly converted into the downward sliding motion of the slider 12, thereby simplifying the structure of the folding joint 1 and the whole crib.

Referring to fig. 7-11, the chassis 20 includes a bottom frame rod 201 and a lifting turnover mechanism 2, the lifting turnover mechanism 2 is used for operating a plurality of bottom frame rods 201 to fold or unfold, the lifting turnover mechanism 2 further includes a drawing combined core 21, a sleeve seat 22 and a bottom cover 23, the sleeve seat 22 is of a hollow sleeve-shaped structure, and includes a sliding sleeve cavity 222 with an axis extending vertically along the up-down direction, the drawing combined core 21 is inserted and matched in the sliding sleeve cavity 222 in a vertically sliding manner, as shown in fig. 8, a sliding groove 210 extending vertically is provided on the drawing combined core 21, and a sliding block 220 in the sliding groove 210 is fixedly provided in the sleeve seat 22. The bottom rack rods 201 are symmetrically distributed around the sleeve seat 22 in pairs, the inner ends of the bottom rack rods 201 are rotatably connected with the sleeve seat 22, the bottom cover 23 is fixedly connected below the sleeve seat 22 and seals the bottom opening of the sleeve seat 22, and decorative rods 202 which are arranged corresponding to the number of the bottom rack rods 201 are rotatably connected to the bottom cover 23. Because the lifting and folding mechanism 2 is required to be pressed down in the unfolding process of the crib, the lifting and folding mechanism 2 collides with the ground, and the bottom cover 23 is arranged to help improve the structural strength of the lifting and folding mechanism 2.

As shown in fig. 9 and 10, the pull-and-push combined core 21 further includes a handle 211, a handle swing seat 212, a straight tooth sleeve 213, a handle rotating disc 215, a lock pin 216, a lock pin guide seat 217 and a lower cover 218, wherein the handle rotating disc 215 is rotatably fitted in a sliding sleeve cavity 222 of the sleeve seat 22, so that the handle rotating disc 215 can also rotate along a vertical axis, the handle 211 is disposed at the top end of the pull-and-push combined core 21 as a force application part, the handle 211 and the handle rotating disc 215 are coaxially connected, specifically, the handle rotating disc 215 includes a disc body 2151 and a coupling shaft 2152 fixedly connected to the upper end surface of the disc body 2151, the coupling shaft 2152 protrudes upward, and the handle 211 is in pin connection with the coupling shaft 2152, so that the handle 211 can also rotate along the vertical axis.

The upper end of the coupling shaft 2152 is in a cut-edge circular shape and is used for being inserted into a cut-edge circular hole 2121 arranged on the handle swinging seat 212 so as to realize the shaft-hub connection of the handle swinging seat 212 and the handle rotating disc 215. The handle 211 is connected with the connecting shaft 2152 through pins, and the plug 2600 for realizing the pin connection of the handle 211 and the connecting shaft 2152 is also connected with the handle swinging seat 212 in a rotatable way, and the plug 2600 is horizontally arranged, so that the handle 211 can swing along a horizontal axis, the handle 211 can have two horizontal and vertical postures, the handle swinging seat 212 is provided with a sinking groove 2120 for accommodating the handle 211, a first arm of the torsion spring 2700 acts on the handle swinging seat 212, and a second arm of the torsion spring 2700 acts on the handle 211, so that the overturning reset of the handle 211 is realized. In the unfolded state, the handle 211 is horizontally accommodated in the countersink 2120 on the handle swing seat 212, and when the handle 211 needs to be operated, the handle 211 is turned over and raised first, and then the handle 211 can be pulled upwards or the handle 211 can be rotated along the vertical axis.

The spur gear sleeve 213 has a cylindrical structure with both ends open, and four sets of racks 2131 extending in the up-down direction corresponding to the four bottom frame rods 201 are provided on the outer periphery thereof. In the present embodiment, the rack 2131 has a sawtooth groove structure recessed on the outer periphery of the straight-tooth socket 213, and in other embodiments, the rack 2131 may be provided protruding on the outer peripheral wall surface of the straight-tooth socket 213, but in this case, the inner wall of the socket 22 needs to be configured to be a structure in which the rack 2131 is unseated. The coupling shaft 2152 of the handle turn disc 215 passes upwardly through the spur gear sleeve 213. The lock pin guide seat 217 is arranged at the lower end of the handle rotating disc 215, the lower cover 218 is arranged at the lower end of the lock pin guide seat 217, the lower cover 218, the lock pin guide seat 217 and the straight tooth sleeve 213 are fixedly connected together through the screw 2300, the disc 2151 of the handle rotating disc 215 is clamped between the straight tooth sleeve 213 and the lock pin guide seat 217, and the handle rotating disc 215 is provided with a yielding groove 2154 for yielding the screw 2300. Pulling the handle 211 can pull the whole drawing combination core 21 to rise in the sliding sleeve cavity 222 of the sleeve seat 22, or applying a force to press down the drawing combination core 21 can make the drawing combination core 21 to descend in the sliding sleeve cavity 222 of the sleeve seat 22. The straight tooth sleeve 213, the handle turn plate 215, and the lock pin guide 217 have linear grooves 2130, 2150, 2170 formed on the outer circumference thereof, respectively, to form the slide groove 210.

As shown in fig. 11, an arc-shaped tooth 2011 is fixedly connected to the inner end of the chassis rod 201, the arc-shaped tooth 2011 is in the shape of an incomplete gear with a plurality of gear teeth arranged in an arc shape, the arc-shaped tooth 2011 is specifically arranged on a sleeve head 2800, the sleeve head 2800 is fixedly sleeved on the inner end of the chassis rod 201, as shown in fig. 8, a window 221 is arranged on a sleeve seat 22, and the arc-shaped tooth 2011 of the chassis rod 201 rotatably connected to the sleeve seat 22 extends into an inner cavity of the sleeve seat 22 from the window 221 and is meshed with a rack 2131. As shown in fig. 12 and 13, when the drawing combined core 21 (straight-tooth sleeve 213) is lifted, the bottom hack lever 201 is driven to fold by the gear connection of the arc-shaped tooth 2011 and the rack 2131, and when the drawing combined core 21 (straight-tooth sleeve 213) is lowered, the bottom hack lever 201 is driven to horizontally unfold by the gear connection of the arc-shaped tooth 2011 and the rack 2131. In this embodiment, the lifting and folding mechanism 2 and the bottom rack bar 201 are in transmission connection through gear engagement, so that the lifting and folding mechanism 2 and the bottom rack bar 201 have transmission linkage relation, especially when the lifting and folding mechanism 2 and the drawing and folding combined core 21 are pressed down in the folding state of the crib, the lifting and folding mechanism 2 is transferred to the bottom rack bar 201 through the gear connection of the arc-shaped tooth part 2011 and the rack 2131, once the drawing and folding combined core 21 descends in place in the sliding sleeve cavity 222, the bottom rack bar 201 is always kept in the horizontal unfolding state under the gear engagement.

A horizontally extending linear guide groove 2171 is arranged on the lock pin guide seat 217 which is closely attached to the lower end of the handle rotating disc 215, the lock pin 216 is in sliding fit in the linear guide groove 2171, a guide post 2161 is fixedly arranged at the upper end of the lock pin 2161, an arc-shaped guide groove 2153 is arranged at the lower end of the handle rotating disc 215, the outer edge of the arc-shaped guide groove 2153 is in an arc shape which is gradually bent from the radial outer end of the handle rotating disc 215 to the radial inner end, and the guide post 2161 is inserted in the arc-shaped guide groove 2153. The first end of the elastic reset piece 219 acts on the lock pin guide seat 217, the second end of the elastic reset piece 219 acts on the lock pin 216, so that the lock pin 216 has a radial outward movement trend, a lock hole 223 is formed in the sleeve seat 22, when the lifting and folding mechanism 2 is not unlocked, the lock pin 216 is inserted into the lock hole 223, so that the drawing and folding core 21 cannot slide in the sleeve seat 22, namely the bottom rack rod 201 cannot be folded, after the lifting handle 211 is rotated along the vertical axis, the outer edge of the arc-shaped guide groove 2153 of the lifting handle rotating disc 215 pushes the lock pin 216 to move radially inwards and separate from the lock hole 223, and at the moment, the lifting and folding mechanism 2 is unlocked, and the lifting handle 211 is pulled upwards to pull the whole drawing and folding core 21, so that the bottom rack rod 201 is folded.

The handle turn plate 215, the latch guide 217, the latch 216, the elastic restoring member 219, and the latch hole 223 constitute a second locking mechanism 2200 for locking the lift-folding mechanism 2. The unlocking of the lift and fold mechanism 2 is achieved by rotating the handle 211 on the vertical axis, that is, the rotational travel of the handle 211 on the vertical axis is the second unlocking travel of the second locking mechanism 2200.

In this embodiment, a linkage mechanism is further provided between the lifting and folding mechanism 2 and the folding joint 1, so that the movements of the lifting and folding mechanism 2 and the folding joint 1 can be linked together. The linkage mechanism specifically includes a first linkage structure (the first linkage structure is a first pull wire 32) and a second linkage structure (the second linkage structure is a rotary linkage 43 and a second pull wire 31), where the first linkage structure is used to link the handle 211 and the slider 12, so that the second unlocking stroke of the handle 211 can trigger the first unlocking stroke of the slider 12, that is, the folding joint 1 is unlocked while the lifting and turning mechanism 2 is unlocked. The second linkage structure is used to link the bottom bracket bar 201 and the foldable cross bar 101 such that the foldable cross bar 101 is also unfolded when the bottom bracket bar 201 is unfolded.

The first linkage structure is a first pull wire 32 in this embodiment, the upper end of the first pull wire 32 is connected to the slider 12, and the lower end of the first pull wire 32 extends into the lifting turnover mechanism 2 and is in linkage connection with the handle 211, so that the slider 12 can be pulled to slide by rotation of the handle 211. On the wiring, the first pull wire 32 in this embodiment is extended along the foldable cross bar 101, the vertical bar 102, and the decorative bar 202 in this order from the upper end to the lower end thereof. The decoration rod 202 is rotatably connected to the bottom cover 23, the hinge point of which is lower than the hinge points of the underframe rod 201 and the sleeve seat 22, the vertical rod 102 and the decoration rod 202 are hollow structures, and the first pull wire 32 passes through the rod bodies of the vertical rod 102 and the decoration rod 202. The lower end of the first pull wire 32 penetrating from the lower decorative rod 202 extends upwards to penetrate into the lifting turnover mechanism 2 and is connected with the lifting handle 211 in a linkage way. Regarding the linkage connection between the lower end of the first pull wire 32 and the handle 211, the lower end of the first pull wire 32 may be directly fixed to the handle 211, so that the handle 211 may be rotated to directly pull the pull wire 32, but another scheme is adopted in this embodiment to link the handle 211 and the lower end of the first pull wire 32. As shown in fig. 9, the pull-combined core 21 further includes a lifting sleeve 214, and the lifting sleeve 214 is sleeved on the coupling shaft 2152 and is located in the inner cavity of the straight tooth sleeve 213. The tray 2151 is provided with a first slope 2153, the lifting sleeve 214 is provided with a second slope 2141, the first slope 2153 and the second slope 2141 are in interference to form an inclined guide fit, and when the tray 2151 rotates, the lifting sleeve 214 or the lifting sleeve 214 is jacked up through the inclined guide fit of the first slope 2153 and the second slope 2141 to naturally fall under the gravity. The lower end of the first wire 32 is fixedly connected to the lifting sleeve 214, so that the lifting handle 211 has a larger stroke of pulling the first wire 32 upwards. Since the lower end of the first wire 32 is to be threaded, the structure of the lifting and folding mechanism 2, such as the latch guide 217 and the tray 2151 of the lower cover 218, is provided with a threading hole (e.g., the threading hole 2400 of the lower cover 218).

As shown in fig. 6, the slider 12 and the guide holder 13 are aligned vertically, the guide holder 13 is provided with a guide channel 132, in this embodiment, the guide channel 132 is only a vertical channel extending vertically, and the first wire 32 passes through the guide channel 132 to make the upper end of the first wire 32 extend vertically in the vertical direction. The guiding effect of the guiding channel 132 is that the first pull wire 32 is always vertical up and down no matter how it extends, so when the first pull wire 32 is pulled, the acting force of the upper end of the first pull wire 32 on the slider 12 is also vertical downward, and no component force in other directions exists, so that the first pull wire 32 can reliably pull the slider 12. Meanwhile, it should be noted that, since the guide channel 132 is in a tunnel-like structure, the guide channel 132 can also limit the first pull wire 32, so as to prevent the first pull wire 32 from winding with other components due to factors such as shaking and stretching.

In this embodiment, the first pull wire 32 is bent from its upper end through the guide channel 132 and then extends in the left-right direction. In other embodiments, a ninety degree arc channel may be further connected below the vertical guide channel 132, and the first wire 32 is guided to extend in the left-right direction through the arc channel after passing through the vertical guide channel 132 from the upper end thereof, so as to ensure that the first wire 32 does not deviate in the direction of the curve.

In this embodiment, the second linkage structure includes a rotary linkage member 43 and a second pull wire 31, as shown in fig. 14, and referring to fig. 3 and 6, the support 4 includes a housing 40, a caster 42 with a brake, and a frame 41, the housing 40 is fixedly connected to the outer side of the frame 41, the caster 42 with a brake is fixedly connected to the frame 41, the rotary linkage member 43 is rotatably connected to the frame 41, and the outer end of the underframe rod 201 is rotatably connected to the frame 41, so that the underframe rod 201 can turn between two vertical and horizontal extreme positions relative to the frame 41 (the rotation center is point E). The rotation range of the bottom frame bar 201 and the frame body 41 can be limited by the cooperation of the limit pins 50 and the arc-shaped grooves 113 similar to those described above. The rotary linkage member 43 of the present embodiment is a sheet structure, and is bent and extended at an obtuse angle, the rotary linkage member 3 is hinged to the frame 41 (the hinge point is point F), and a first connection portion 432 and a second connection portion 431 are respectively disposed at two sides of the hinge point of the rotary linkage member 43 and the frame 41, where the first connection portion 432 is used for fixing the lower end of the second wire 31, and in the present embodiment, the first connection portion 432 is a through hole and is fixed with the lower end of the second wire 31 through a latch structure. The second connection portion 431 is a bar-shaped groove, one end of the underframe rod 201 is hinged in the second connection portion 431, specifically, a U-shaped notch 2012 is formed at the outer end of the underframe rod 201, a pin 500 is fixedly inserted into the U-shaped notch 2012, the rotation linkage 43 is inserted into the U-shaped notch 2012, and the pin 500 is arranged through the second connection portion 431.

The present utility model is configured such that the chassis rod 201 and the rotary linkage 43 are movably hinged to each other by the pin 500 and the second connection portion 431, and both have a relative movement and a relative rotation relationship, as shown in fig. 15-17, and in this embodiment, the rotary linkage 43 is configured to: when the underframe bar 201 is located at the vertical limit position, the bar-shaped groove of the first connecting portion 432 extends horizontally, the pin 500 abuts against one end of the bar-shaped groove of the first connecting portion 432 far away from the hinge point F, and the bar-shaped groove of the first connecting portion 432 provides a horizontal displacement space for the outer end of the underframe bar 201. Then, when the bottom bracket bar 201 is turned over from vertical to horizontal, there is no dead point of the rotation linkage 43, in other words, the bottom bracket bar 201 can be folded to a vertical limit position, so that the crib can be folded to a smaller volume, and the occupied space is small, and the rotation linkage 43 can be replaced with a conventional link structure in other embodiments, without considering this effect. In other embodiments, the pin 500 does not need to be abutted against the end of the bar-shaped groove of the first connection portion 432 away from the hinge point F, for example, the pin 500 is located in the middle of the bar-shaped groove of the first connection portion 432, but the pin 500 of this embodiment is abutted against the end of the bar-shaped groove of the first connection portion 432 away from the hinge point F and can also have a limiting effect on the chassis rod 201.

Meanwhile, in the present embodiment, the rotation linkage member 43 is a bending extension structure with an obtuse angle, and the hinge point F is disposed at the bending position of the rotation linkage member 3, as shown in fig. 15, so that the movement track H of the first connecting portion 32 is substantially in the vertical direction (the movement track H is in the vertical direction as a whole), so that the second pull wire 31 is not excessively stretched in the horizontal direction, and the problems of friction, interference, and the like of the second pull wire 31 and other structures are avoided.

The upper end of the second wire 31 is fixedly connected to the first folding bar 1011 or the second folding bar 1012 (the first folding bar 1011 or the second folding bar 1012 are respectively provided with the second wire 31), on the wiring, the second wire 31 extends from the upper end thereof along the foldable cross bar 101 left and right and then vertically downwards along the vertical bar 102 to the support 4, and the second wire 31 runs in the hollow vertical bar 102. When the chassis lever 201 is unfolded, the second stay 31 is pulled by rotating the linkage 43 such that the second stay 31 pulls the first folding lever 1011 and the second folding lever 1012 to unfold to straighten the foldable cross bar 101 to the locked state.

In addition to the pull wires, the first pull wire 32 and the second pull wire 31 may be replaced by other linear transmission structures in other embodiments, for example, each folded section of the pull wire is replaced by a rigid straight rod, each folded section of the pull wire is replaced by a connecting rod/rotating disc linkage structure, that is, several rigid straight rods are connected in sequence, and the connecting parts are connected by the connecting rod/rotating disc linkage structure for pulling force linkage, which is also feasible, but the pull wires are not as easy to be folded as flexible when the baby crib is folded, and the weight is also larger.

Referring to fig. 2, 18, 19, the folding and unfolding principle of the present embodiment is as follows:

1. folding: when the crib is in an unfolding state, the folding joint 1 and the lifting turnover mechanism 2 are both in a locking state, and the underframe rod 201 and the foldable cross rod 101 are both horizontal. The handle 211 is manually rotated, the handle 211 unlocks the second locking mechanism 2200, and simultaneously the sliding block 12 is pulled through the first pull wire 32 to unlock the first locking mechanism 1100, at this time, the folding joint 1 is unlocked, the foldable cross rod 101 is changed from a horizontal locking state to a loose unlocking state of downwards concave bending under the influence of gravity, the handle 211 is lifted upwards, the bottom hack lever 201 is driven to fold downwards through the gear connection of the arc-shaped tooth part 2011 and the rack 2131, and meanwhile, the vertical rod 102 is pulled to approach towards the center, so that the foldable cross rod 101 is further folded.

2. The unfolding process comprises the following steps: when the crib is in a folded state, the handle 211 is pressed down, the bottom hack lever 201 is driven to be unfolded through the gear connection of the arc-shaped tooth part 2011 and the rack 2131, and meanwhile, the bottom hack lever 201 pulls the second stay wire 31 through the rotary linkage 43, so that the second stay wire 31 pulls the first folding lever 1011 and the second folding lever 1012 to straighten the foldable cross bar 101 to a locked state.

The foldable crib of the embodiment realizes that the unfolding and folding processes can be realized only by applying force at one position of the lifting and folding mechanism 2 through the first linkage structure and the second linkage structure, and the folding joint 1 does not need to be operated. Realizes one-step unfolding or folding of the foldable crib and simplifies the manual operation of the crib. During the folding process, the unlocking of the folding joint 1 and the lifting turnover mechanism 2 can be synchronously realized by only rotating the lifting handle 211 by means of the linkage of the first pull wire 32; during the unfolding process, the synchronous unfolding of the underframe bar 201 and the foldable cross bar 101 is reliably achieved by means of the linkage of the rack-and-pinion structure formed by the arc-shaped tooth 2011 and the rack 2131, the second stay wire 31 and the rotary linkage 43.

While the utility model has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims (14)

1. The utility model provides a collapsible crib, includes side rail and chassis, and the side rail includes collapsible horizontal pole, and collapsible horizontal pole has first locking mechanical system, and first locking mechanical system is used for locking the folding action of collapsible horizontal pole when collapsible crib is expanded, and the chassis is including carrying to draw folding mechanism, carries to draw folding mechanism to have second locking mechanical system, and second locking mechanical system is used for locking to carry when collapsible crib is expanded and draws folding mechanism's folding action, its characterized in that: the foldable cross rod further comprises a movable unlocking piece, the movable unlocking piece is provided with a first unlocking stroke for unlocking the first locking mechanism, the lifting turnover mechanism further comprises a lifting handle, the lifting handle is provided with a second unlocking stroke for unlocking the second locking mechanism, the foldable cross rod further comprises a first linkage structure, and the lifting handle is in linkage connection with the movable unlocking piece through the first linkage structure, so that the second unlocking stroke of the lifting handle can trigger the first unlocking stroke of the movable unlocking piece.

2. The foldable crib of claim 1, wherein: the side fence further comprises a plurality of vertical rods, the foldable cross rods are arranged between the vertical rods and the vertical rods, two ends of each foldable cross rod are respectively and rotatably connected with one vertical rod, the underframe further comprises underframe rods corresponding to the number of the vertical rods, the inner ends of the plurality of underframe rods are mutually gathered and are rotatably connected with the lifting turnover mechanism, and the lower end of each vertical rod is connected with the outer end of one bottom hack lever.

3. The foldable crib of claim 2, wherein: the first linkage structure is a first stay wire, the upper end of the first stay wire is in linkage connection with the movable unlocking piece, and the lower end of the first stay wire is in linkage connection with the handle.

4. A collapsible crib as in claim 3, wherein: the second unlocking stroke is a rotation stroke of the lifting handle on the vertical axis, and the first unlocking stroke is a vertically downward sliding stroke of the movable unlocking piece.

5. The foldable crib of claim 4, wherein: the lifting turnover mechanism further comprises a sleeve seat and a handle rotating disc, wherein the sleeve seat is of a hollow sleeve-shaped structure and comprises a sliding sleeve cavity with an axis extending vertically in the up-down direction, the bottom rack rod is rotatably connected with the sleeve seat, the handle rotating disc is rotatably matched in the sliding sleeve cavity, and the handle rotating disc is coaxially connected with the handle, so that the handle can rotate along the vertical axis.

6. The foldable crib of claim 5, wherein: the second locking mechanism comprises a lock pin, a lock pin guide seat and an elastic reset piece, wherein the lock pin guide seat is tightly attached to the lower end of the handle rotating disc, a linear guide groove which extends horizontally is arranged on the lock pin guide seat, the lock pin is slidably matched in the linear guide groove, a guide pillar is fixedly arranged at the upper end of the lock pin, an arc guide groove is arranged at the lower end of the handle rotating disc, the outer edge of the arc guide groove is in an arc shape which is gradually bent and close to the radial inner end from the radial outer end of the handle rotating disc, the guide pillar is inserted in the arc guide groove, the first end of the elastic reset piece acts on the lock pin guide seat, the second end of the elastic reset piece acts on the lock pin to enable the lock pin to have a trend of radially outwards moving, and a lock hole for being inserted with the lock pin is formed in the sleeve seat.

7. The foldable crib of claim 5, wherein: the lower end of the first pull wire is fixedly connected with the handle/handle rotating disc; or, the handle rotating disc comprises a disc body and a connecting shaft fixed on one end face of the disc body, the handle and the disc body are coaxially connected through the connecting shaft, a lifting sleeve is sleeved on the connecting shaft, a first slope is arranged on the disc body, a second slope is arranged on the lifting sleeve, the first slope and the second slope are in collision to form oblique guide fit, so that the lifting sleeve can be jacked up through the oblique guide fit of the first slope and the second slope when the disc body rotates, and the lower end of the first stay wire is fixedly connected with the lifting sleeve.

8. The foldable crib of claim 4, wherein: the foldable cross rod further comprises a first folding rod, a second folding rod and a folding joint arranged between the first folding rod and the second folding rod, the folding joint comprises a joint base body, the first folding rod and the second folding rod are respectively pivoted at the left end and the right end of the joint base body, the movable unlocking piece is a sliding block which is arranged between the first folding rod and the second folding rod and can slide up and down, and the upper end of the first stay wire is fixedly connected with the sliding block.

9. The foldable crib of claim 8, wherein: the first locking mechanism comprises a first limiting pin and a second limiting pin, a first transverse groove and a second transverse groove which extend left and right are formed in the joint substrate, the first transverse groove and the second transverse groove are respectively close to the first folding rod and the second folding rod and are bilaterally symmetrical, a first chute and a second chute which extend obliquely and are bilaterally mirror symmetrical are formed in the sliding block, the first limiting pin is simultaneously in sliding fit in the first transverse groove and the first chute, the second limiting pin is simultaneously in sliding fit in the second transverse groove and the second chute, and accordingly the upper and lower sliding of the sliding block is converted into the sliding that the first limiting pin and the second limiting pin are synchronously far away from or close to each other in the left and right direction through the first chute and the second chute, and the first limiting pin and the second limiting pin are used for resisting the relative folding of the first folding rod and the second folding rod.

10. The foldable crib of claim 2, wherein: and a second linkage structure for linking the foldable cross bars for relative deployment when the chassis bars are deployed.

11. The foldable crib of claim 10, wherein: the foldable cross rod further comprises a first folding rod, a second folding rod and a folding joint arranged between the first folding rod and the second folding rod, the second linkage structure comprises a rotary linkage piece and a second pull wire, the rotary linkage piece is rotatably arranged at the outer end of the bottom hack lever, the outer end of the bottom hack lever is movably hinged with the rotary linkage piece, the upper end to the lower end of the second pull wire are sequentially arranged along the foldable cross rod and the vertical rod in an extending mode, the upper end of the second pull wire is connected with the first folding rod or the second folding rod, the lower end of the second pull wire is fixedly connected with the rotary linkage piece, and accordingly the second pull wire is pulled through the rotary linkage piece when the bottom hack lever is unfolded, and the first folding rod and the second folding rod are pulled to be unfolded relatively.

12. The foldable crib of claim 11, wherein: still include fixed connection in the support of montant lower extreme, chassis pole rotatable connect in the support and can be relative the support is in vertical and two extreme positions of level are overturned, rotatory linkage with the support is articulated rotatory linkage with hinge point both sides position of support is equipped with first connecting portion and second connecting portion respectively, first connecting portion are used for fixing the second is acted as go-between the lower extreme, the second connecting portion is a bar slot, chassis pole outer end hinge is in the bar slot.

13. The foldable crib of claim 11, wherein: the lifting turnover mechanism further comprises a lifting combined core body and a sleeve seat, the sleeve seat is of a hollow sleeve-shaped structure and comprises a sliding sleeve cavity with an axis extending vertically in the vertical direction, the lifting combined core body can be inserted and matched in the sliding sleeve cavity in a vertically sliding mode, a lifting handle is arranged at the top end of the lifting combined core body, racks which correspond to the number of bottom rack rods and extend in the vertical direction are arranged on the peripheral side of the lifting combined core body, arc-shaped tooth parts are fixedly connected to the inner ends of the bottom rack rods, windows are arranged on the sleeve seat, the bottom rack rods are connected with the sleeve seat in a rotating mode, and the arc-shaped tooth parts of the bottom rack rods extend into the inner cavity of the sleeve seat from the windows and are correspondingly meshed with the racks.

14. The foldable crib of claim 13, wherein: the pull combination core further comprises a straight tooth sleeve, a handle rotating disc, a lock pin guide seat and a lower cover, wherein the handle rotating disc is rotatably matched in the sliding sleeve cavity, the handle rotating disc comprises a disc body and a connecting shaft fixed on one end face of the disc body, the handle and the disc body are coaxially connected through the connecting shaft, the straight tooth sleeve is of a hollow cylindrical structure with two open ends, the connecting shaft penetrates through the straight tooth sleeve, the lock pin guide seat is arranged at the lower end of the handle rotating disc, the lower cover is arranged at the lower end of the lock pin guide seat, the straight tooth sleeve, the lock pin guide seat and the lower cover are fixedly connected through screws, a yielding groove for the screws to penetrate is formed in the handle rotating disc, and the rack is fixedly arranged at the periphery of the straight tooth sleeve.

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