阅读说明：本技术 一种座椅架大幅可调的摇椅 (Rocking chair with seat frame capable of being adjusted substantially ) 是由 程美容 于 2021-04-06 设计创作，主要内容包括：本发明公开了一种座椅架大幅可调的摇椅,它包括底座、弧形摇架以及座椅架,底座与弧形摇架底面通过限位结构连接,弧形摇架与底座通过曲柄连杆机构相连,固定在底座上的电机驱动曲柄连杆机构运动,座椅架通过支撑结构设在弧形摇架上；座椅架分为腿托部分、坐垫部分以及靠背部分；通过设在座椅架内的前、后电动推杆调整椅体架的倾斜幅度。座椅的倾斜幅度在坐、靠、平躺之间切换,满足人们在睡眠时靠睡、平躺睡的多种习惯要求。增柔结构的使用,提供一种飘然的感觉。底座与弧形摇架之间设置两种连接方式,提升了装置的适用性。可调幅的曲柄连杆装置的使用,满足不同人群对摇椅摇摆幅度的需求。(The invention discloses a rocking chair with a greatly adjustable seat frame, which comprises a base, an arc-shaped cradle and the seat frame, wherein the base is connected with the bottom surface of the arc-shaped cradle through a limiting structure; the seat frame is divided into a leg rest part, a cushion part and a backrest part; the inclination amplitude of the chair body frame is adjusted by the front and the rear electric push rods arranged in the chair frame. The inclination range of the chair is switched among sitting, leaning and lying, and various habit requirements of people for sleeping by leaning and lying are met. The use of the stiffening structure provides a feeling of freshness. Two connection modes are arranged between the base and the arc-shaped cradle, so that the applicability of the device is improved. The use of the crank connecting rod device capable of amplitude modulation meets the requirements of different people on the swing amplitude of the rocking chair.)

1. A rocking chair with a substantially adjustable seat frame comprises

The bottom surface of the arc-shaped cradle is connected with the base through a limiting mechanism, the middle part of the arc-shaped cradle is connected with the base through a crank-link mechanism, a motor fixed on the base drives the crank-link mechanism to move, and the seat frame is arranged on the arc-shaped cradle through a supporting device;

it is characterized in that the seat frame is divided into a leg rest part, a cushion part and a backrest part;

the cushion part comprises a fixed bracket arranged on the arc-shaped cradle, a movable bracket connected with the fixed bracket and a front electric push rod used for driving the movable bracket to move, wherein one end of the front electric push rod is connected with the arc-shaped cradle, and the other end of the front electric push rod is connected with the movable bracket;

the leg support part comprises a leg support bracket and a leg support connecting rod group, the front end of the leg support connecting rod group is connected with the leg support bracket, and the rear end of the leg support connecting rod group is connected with the movable bracket;

the backrest part comprises a backrest support and a rear electric push rod, one end of the backrest support is connected with the fixed support, the other end of the backrest support is connected with the rear electric push rod, the other end of the rear electric push rod is connected with the movable support, and the inclination range of the chair body frame is adjusted through the front electric push rod and the rear electric push rod.

2. A rocking chair with substantially adjustable seat frame as claimed in claim 1, wherein: the movable support adopts a double-crank mechanism and comprises a first connecting rod and a first rack which are arranged in parallel from top to bottom, and a first crank and a second crank which are used for connecting the first connecting rod and the first rack, wherein the first rack is fixedly arranged on the fixed support.

3. A rocking chair as claimed in claim 2, wherein the seat frame is substantially adjustable: the seat frame is symmetrically arranged, the first connecting rods of the movable supports on the two sides are connected through the middle supporting rod, and the fixed supports are connected through the cross pull rod.

4. A rocking chair with substantially adjustable seat frame as claimed in claim 2 or 3, wherein: the rear electric push rod is hinged with the first connecting rod, and the front electric push rod is hinged with the middle push rod.

5. A rocking chair with substantially adjustable seat frame as claimed in claim 2 or 3, wherein: the leg support connecting rod set comprises a four-connecting-rod mechanism formed by mutually hinging a first supporting rod, a second supporting rod, a third supporting rod and a fourth supporting rod, wherein the first supporting rod at the front side is hinged with the leg support bracket through a straight rod and the extending end of the second supporting rod, and the third supporting rod at the rear side is hinged with the first crank and the first connecting rod respectively and the extending end of the fourth supporting rod.

6. A rocking chair with substantially adjustable seat frame as claimed in claim 2 or 3, wherein: the supporting device comprises a fixed support arranged on the front side of the arc-shaped cradle and a flexibility increasing structure arranged on the rear side of the arc-shaped cradle; the front side of the seat frame is hinged on the fixed support, and the rear side of the seat frame is connected with the arc-shaped cradle through the flexibility increasing structure.

7. A rocking chair with substantially adjustable seat frame as claimed in claim 6, wherein: the flexibility increasing structure comprises a flexibility increasing support arranged on the arc-shaped rocking frame, a flexibility increasing crank with the middle part hinged on the fixed support and a spring used for connecting the arc-shaped rocking frame and the seat frame; the top of the flexible support is provided with a clamping groove, one end of the flexible crank is provided with a clamping bolt matched with the clamping groove, and the other end of the flexible crank is hinged on the first connecting rod through a connecting rod.

8. A rocking chair with substantially adjustable seat frame as claimed in claim 1 or 2, wherein: the crank-link mechanism is amplitude-adjustable and comprises a crank and a link rod which are connected with the motor, a chute, a slide block and a first electric push rod, wherein the chute, the slide block and the first electric push rod are arranged on the arc-shaped cradle and push the slide block to move in the chute; wherein the slider is articulated with the connecting rod end, and first electric putter one end is fixed in the middle part of the arc cradle, and the other end is fixed on the slider.

9. A rocking chair with substantially adjustable seat frame as claimed in claim 1 or 2, wherein: the limiting mechanism adopts chain conveying belts arranged in pairs; one end of each chain crossing belt is fixed on the ground of the arc rod, the other end of each chain crossing belt is fixed on the base, and the same pair of chain crossing belts form non-contact interval crossing at the lowest position of the arc rod; at least two sets of cross-linking belts are included.

10. A rocking chair with substantially adjustable seat frame as claimed in claim 1 or 2, wherein: the limiting mechanism adopts a linear rack and an arc rack which are meshed with each other, the linear rack is arranged on the base, the arc rack is arranged on the bottom surface of the arc rod cradle, and the arc rod is guaranteed to swing in a preset track through mutual engagement of the racks.

Technical Field

The invention relates to the field of household nursing equipment, in particular to a rocking chair with a greatly adjustable seat frame.

Background

The rocking chair is a common daily article in daily life, and is different from a common chair in that the rocking chair can rock back and forth, so that people sitting on the rocking chair feel more comfortable and can have a better rest. The rocking chair enables people to be sleepy while making the people leisure, and in terms of sleeping, many people are more used to lie down to fall asleep, and at the moment, the people need to move from the rocking chair to the bed to continue to fall asleep, but the moving process is easy to interrupt sleepiness, so that the people are in a situation that the people cannot sleep.

For example, chinese patent 201020175064.2 discloses an adjustable electric reclining chair, which is characterized in that a driving device is arranged below a chair seat, the driving device is connected with a crank-link mechanism, a sliding groove, a sliding block and an electric push rod for pushing the sliding block to move are further arranged on the side surface of the chair seat, wherein the sliding block is hinged with the tail end of a connecting rod of the crank-link mechanism, and the electric push rod is controlled by a switch arranged on a handrail. The electric reclining chair has the following defects: firstly, the deck chair is the form of "chair" all the time, and back and leg support can only increase inclination, but the deck chair can not adjust to the level, and many people that are used to lie flat to fall asleep need change to the bed before falling asleep, and the process of moving one's step loses the drowsiness easily. Secondly, the seat frame is connected with the cradle through the support, and is in hard contact, and the comfort needs to be improved.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the rocking chair with the greatly adjustable seat frame and the horizontally-lying seat frame

The technical scheme adopted by the invention is as follows: a rocking chair with a greatly adjustable seat frame comprises a base, an arc-shaped rocking frame and a seat frame, wherein the bottom surface of the arc-shaped rocking frame is connected with the base through a limiting mechanism, the middle part of the arc-shaped rocking frame is connected with the base through a crank-link mechanism, a motor fixed on the base drives the crank-link mechanism to move, and the seat frame is arranged on the arc-shaped rocking frame through a supporting device; it is characterized in that the seat frame is divided into a leg rest part, a cushion part and a backrest part; the cushion part comprises a fixed bracket arranged on the arc-shaped cradle, a movable bracket connected with the fixed bracket and a front electric push rod used for driving the movable bracket to move, wherein one end of the front electric push rod is connected with the arc-shaped cradle, and the other end of the front electric push rod is connected with the movable bracket; the leg support part comprises a leg support bracket and a leg support connecting rod group, the front end of the leg support connecting rod group is connected with the leg support bracket, and the rear end of the leg support connecting rod group is connected with the movable bracket; the backrest part comprises a backrest support and a rear electric push rod, one end of the backrest support is connected with the fixed support, the other end of the backrest support is connected with the rear electric push rod, the other end of the rear electric push rod is connected with the movable support, and the inclination range of the chair body frame is adjusted through the front electric push rod and the rear electric push rod.

According to the technical scheme, the movable support adopts a double-crank mechanism and comprises a first connecting rod and a first rack which are arranged in parallel from top to bottom, and a first crank and a second crank which are used for connecting the first connecting rod and the first rack, wherein the first rack is fixedly arranged on the fixed support.

According to the technical scheme, the seat frames are symmetrically arranged, the first connecting rods of the movable supports on the two sides are connected through the middle supporting rod, and the fixed supports are connected through the cross pull rod.

According to the technical scheme, the rear electric push rod is hinged with the first connecting rod, and the front electric push rod is hinged with the middle push rod.

According to the technical scheme, the leg support connecting rod group comprises a four-bar mechanism formed by mutually hinging a first supporting rod, a second supporting rod, a third supporting rod and a fourth supporting rod, wherein the first supporting rod at the front side is hinged with the leg support bracket through a straight rod and the extension end of the second supporting rod, and the third supporting rod at the rear side is hinged with the first crank and the first connecting rod respectively and the extension end of the fourth supporting rod.

According to the technical scheme, the supporting device comprises a fixed support arranged on the front side of the arc-shaped cradle and a flexibility increasing structure arranged on the rear side of the arc-shaped cradle; the front side of the seat frame is hinged on the fixed support, and the rear side of the seat frame is connected with the arc-shaped cradle through the flexibility increasing structure.

According to the technical scheme, the flexibility increasing structure comprises a flexibility increasing support arranged on the arc-shaped rocking frame, a flexibility increasing crank hinged to the fixed support at the middle part and a spring used for connecting the arc-shaped rocking frame and the seat frame; the top of the flexible support is provided with a clamping groove, one end of the flexible crank is provided with a clamping bolt matched with the clamping groove, and the other end of the flexible crank is hinged on the first connecting rod through a connecting rod.

According to the technical scheme, the crank-link mechanism is amplitude-adjustable and comprises a crank and a link rod which are connected with a motor, a chute, a sliding block and a first electric push rod, wherein the chute, the sliding block and the first electric push rod are arranged on an arc-shaped cradle; wherein the slider is articulated with the connecting rod end, and first electric putter one end is fixed in the middle part of the arc cradle, and the other end is fixed on the slider.

According to the technical scheme, the limiting mechanism adopts chain conveying belts which are arranged in pairs; one end of each chain crossing belt is fixed on the ground of the arc rod, the other end of each chain crossing belt is fixed on the base, and the same pair of chain crossing belts form non-contact interval crossing at the lowest position of the arc rod; at least two sets of cross-linking belts are included.

According to the technical scheme, the limiting mechanism adopts the linear rack and the arc rack which are meshed with each other, the linear rack is arranged on the base, the arc rack is arranged on the bottom surface of the arc rod cradle, and the arc rod is guaranteed to swing in a preset track through mutual meshing of the racks.

The beneficial effects obtained by the invention are as follows:

1. the movable support is used, so that the inclination angles of the backrest part and the leg support part are synchronously adjusted through the front electric push rod, the leg support part can be adjusted to be horizontal through the leg support connecting rod group, and the angle of the backrest part can be independently adjusted through the rear electric push rod; the implementation of the measures enables the rocking chair to be switched between the reclining chair forms with different inclination angles and the lying state, and adapts to the habit that many people need to lie flat when sleeping.

2. The rear side of seat frame sets up the use that increases gentle structure as the back support, when deck chair through preceding electric putter shrink adjustment deck chair inclination, the movable support can drive and increase gentle crank anticlockwise rotation, make the card bolt that increases gentle crank break away from the draw-in groove that increases gentle support, the back supporting mode of the chair body is switched into "soft support" by the spring by "hard support" that increases gentle crank and increase gentle support, make the rocking chair have the sense of waving of an up-and-down fluctuation, the travelling comfort of rocking chair has been promoted.

3. Set up the connected mode between two kinds of bases and the arc cradle, can be according to the different scenes that are suitable for and switch, promoted the suitability of device.

4. The application of the crank-link mechanism with amplitude modulation meets the requirements of different people on the swing amplitude of the rocking chair.

Drawings

FIG. 1 is an external structural view of an embodiment of the present invention;

FIG. 2 is a schematic diagram of the internal structure of the embodiment of the present invention;

FIG. 3 is a schematic view of a connection structure between a single-sided chair body frame and an arc-shaped rocking frame according to an embodiment of the present invention;

FIG. 4 is a schematic view of an adjustable-web crank-link mechanism according to an embodiment of the present invention;

FIG. 5 is a schematic view of a chain transfer belt between a base and an arc cradle according to an embodiment of the present invention;

FIG. 6 is a schematic view of another connection structure between the base and the cradle according to the embodiment of the present invention;

in the figure: 1. the device comprises a base, 2, an arc-shaped cradle, 3, a seat frame, 4, a chain-crossing belt, 4-1, a first chain-crossing belt, 4-2, a second chain-crossing belt, 5, a rack, 5-1, a straight-line-shaped rack, 5-2, an arc-shaped rack, 6, a motor, 7, a crank-link mechanism, 7-1, a crank, 7-2, a link, 7-3, a chute, 7-4, a sliding block, 7-5, a first electric push rod, 7-6, a driving arm, 8, a fixed support, 9-1, a first link, 9-2, a first frame, 9-3, a first crank, 9-4, a second crank, 10, a front electric push rod, 11, a middle supporting rod, 12, a leg-supporting support, 13, a leg-supporting-link group, 13-1, a first supporting rod, 13-2, a second supporting rod, 13-3, a first chain-crossing belt, 4, 13-4 parts of a third supporting rod, 14-1 parts of a fourth supporting rod, 14-2 parts of a common straight rod, 14-3 parts of a common straight rod, 15 parts of a rear electric push rod, 16 parts of a fixed support, 17 parts of a flexibility increasing structure, 17-1 parts of a flexibility increasing support, 17-2 parts of a flexibility increasing crank, 17-3 parts of a spring, 18 parts of an auxiliary rail, 18-1 parts of a rail frame, 18-2 parts of a rail wheel, 19 parts of a backrest support.

Detailed Description

The present invention will be described in further detail below with reference to specific embodiments and with reference to the accompanying drawings.

Referring to fig. 1 to 5, the present invention provides a rocking chair with a greatly adjustable seat frame, which comprises a base 1, an arc-shaped rocking frame 2 and a seat frame 3. The base 1 is connected with the bottom surface of the arc-shaped cradle 2 through a limiting mechanism, so that the arc-shaped cradle 2 is limited to only swing back and forth on the base 1; the limiting structure can adopt chain belts 4 arranged in pairs or mutually meshed racks 5. The middle part of the arc-shaped cradle 2 is connected with the base 1 through a crank-link mechanism 7, the motor 6 fixed on the base 1 drives the crank-link mechanism 7 to move, the crank-link mechanism 7 drives the arc-shaped cradle 2 to do reciprocating motion on the base 1, and the seat frame 3 is arranged on the arc-shaped cradle 2 through a supporting device.

The seat frame 3 adopts a bilateral symmetry structure and is divided into a front part, a middle part and a rear part which are respectively a leg support part, a cushion part and a backrest part. The specific structural design is as follows:

the cushion part comprises a fixed support 8, a movable support and a front electric push rod 10, and the cushion is fixed on the fixed support 8 in a soft package mode. The movable support adopts a parallelogram mechanism in a double-crank mechanism, and comprises a first connecting rod 9-1 and a first frame 9-2 which are arranged in parallel, and a first crank 9-3 and a second crank 9-4 which are connected with the first connecting rod and the first frame 9-2, wherein the first connecting rod and the first frame 9-2 are hinged with each other, the first frame 9-2 is fixedly arranged on a fixed support 8, and the first connecting rod 9-1 is positioned above the first frame 9-2. The seat frame 3 adopts a bilateral symmetry structure, the fixed brackets 8 on the left side and the right side are fixedly connected through a transverse pull rod, and the first connecting rods 9-1 on the left side and the right side are fixedly connected through a middle supporting rod 11. One end of the front electric push rod 10 is hinged on the arc-shaped cradle 2, and the other end is hinged on the middle supporting rod 11. The front electric push rod 10 can indirectly drive the first crank 9-3 and the second crank 9-4 to rotate around the hinged end of the first frame 9-2 by driving the middle support rod 11 and the first connecting rod 9-1; the first connecting rod 9-1 and the first frame 9-2 are always ensured to be parallel in the movement process. In addition, the first crank 9-3 is provided with a bent extension end.

The leg support part comprises a leg support bracket 12 and a leg support connecting rod group 13, and the leg support soft bag is fixed on the leg support bracket 12. The leg support connecting rod group 13 comprises a four-bar linkage mechanism formed by mutually hinging a first supporting rod 13-1, a second supporting rod 13-2, a third supporting rod 13-3 and a fourth supporting rod 13-4. The first supporting rod 13-1 and the second supporting rod 13-2 are positioned at the front side of the leg support connecting rod group 13, the extending ends of the first supporting rod and the second supporting rod are connected with the leg support bracket 12 through common straight rods 14-1 and 14-2, and the leg support bracket 12 is hinged at the other ends of the common straight rods 14-1 and 14-2. The third supporting rod 13-3 and the fourth supporting rod 13-4 are positioned at the rear side of the leg support connecting rod group 13, the extension end of the third supporting rod 13-3 is hinged with the extension end of the first crank 9-3, and the fourth supporting rod 13-4 is hinged with the first connecting rod 9-1. Preferably, the fourth strut 13-4, the first link 9-1 and the middle strut 11 may share a common hinge point. When the front electric push rod 10 is lengthened or shortened, the first crank 9-3 is rotated clockwise or counterclockwise around a hinge point thereof with the first frame 9-2, and an angle between the first crank 9-3 and the first connecting rod 9-1 is increased or decreased; thereby adjusting the position and angle of the leg rest bracket 12 through the four-bar linkage of the leg rest linkage 13.

The backrest part comprises a backrest support 19 and a rear electric push rod 15, one end of the backrest support 19 is hinged to the fixed support 8, the other end of the backrest support 19 is hinged to the end of the push rod of the rear electric push rod 15, the other end of the rear electric push rod 15 is hinged to the first connecting rod 9-1 of the movable support, and a backrest soft bag is fixed on the backrest support 19. When the front electric putter 10 is retracted, the movable bracket is moved backward so that the back bracket 19 is rotated about the hinge point with the fixed bracket 8, thereby achieving the purpose of adjusting the back bracket 19 and the leg rest bracket 12 at the same time. In addition, the backrest support 19 can also be adjusted by the rear electric push rod 15.

The supporting device in the embodiment comprises a fixed support 16 fixed on the arc-shaped rocking frame 2 and a flexibility increasing structure 17 positioned between the arc-shaped rocking frame 2 and the seat frame 3, the front end of the seat frame 3 is hinged to the fixed support 16, and the rear end of the seat frame 3 is supported by the flexibility increasing structure 17. The flexibility increasing structure 17 comprises a flexibility increasing support 17-1 arranged on the arc-shaped rocking frame 2, a flexibility increasing crank 17-2 with the middle part hinged on the fixed support 8 and a spring 17-3 used for connecting the arc-shaped rocking frame and the seat frame; the top of the flexibility increasing support 17-1 is provided with a clamping groove, one end of the flexibility increasing crank 17-2 is provided with a clamping bolt matched with the clamping groove, and the other end of the flexibility increasing crank is hinged on the first connecting rod 9-1 through a common straight rod 14-3. When the front electric push rod 10 contracts, the movable support moves backwards, so that the flexibility increasing crank 17-2 rotates anticlockwise around a hinge point between the middle part of the flexibility increasing crank 17-2 and the fixed support 8, and the clamping bolt of the flexibility increasing crank 17-2 is separated from the clamping groove of the flexibility increasing support 17-1. The rear portion of the seat frame 3 is now supported by the "hard support" of the increased flexibility mount 17-1 and increased flexibility crank 17-2 to switch the "soft support" of the spring 17-3.

The crank-link mechanism 7 adopted in the embodiment is amplitude-adjustable and comprises a crank 7-1 connected with the motor 6, a link 7-2 hinged with the crank 7-1, a chute 7-3 arranged on the arc cradle 2, a slide block 7-4 and a first electric push rod 7-5 for pushing the slide block 7-4 to move in the chute 7-3. The chute 7-3 is arranged on a driving arm 7-6 in the middle of the arc-shaped cradle 2; the sliding block 7-4 is arranged in the sliding groove 7-3 and can move in the sliding groove 7-3, and the sliding block 7-4 is hinged with the tail end of the connecting rod 7-2. One end of a first electric push rod 7-5 is fixed in the middle of the arc-shaped cradle, and the other end is fixed on the slide block and used for pushing the slide block 7-4 to move in the chute 7-3. The motor 6 drives the crank 7-1 to do circular motion, and the crank 7-1 drives the connecting rod 7-2 to do reciprocating motion. As the sliding block 7-4 is static relative to the driving arm 7-6 under the action of the first electric push rod 7-5, when the connecting rod 7-2 reciprocates, the arc-shaped cradle 2 can be pushed to reciprocate through the sliding block 7-4, and the swinging function of the seat frame 3 is realized. Since the length of the link 7-2 is constant, the displacement of the slider 7-4 in the horizontal direction is close. The first electric push rod 7-5 pushes the height of the slide block 7-4, which is equivalent to that the swing radius of the slide block 7-4 is increased, and the horizontal displacement of the slide block 7-4 is approximately unchanged, so that the swing angle of the slide block 7-4 is reduced, and the function of adjusting the swing amplitude is realized. When the swing amplitude of the rocking chair needs to be increased, the height of the sliding block 7-4 can be reduced.

The limiting mechanism of the embodiment adopts the interlinking chains 4 which are arranged in pairs and at least comprises two interlinking belts. The present embodiment comprises two pairs of intersecting chain belts, wherein the two pairs of intersecting chain belts are arranged symmetrically left and right, and the single pair of intersecting chain belts 4 comprises a first intersecting chain belt 4-1 and a second intersecting chain belt 4-2. One end of the first chain conveying belt 4-1 is fixed at the bottom of the front tilting end of the arc-shaped cradle 2, and the other end is fixed on the upper plane of the base 1 below the rear tilting end of the arc-shaped cradle 2. On the contrary, one end of the second chain conveying belt 4-2 is fixed at the bottom of the rear tilting end of the arc-shaped cradle 2, and the other end is fixed on the upper plane of the base 1 below the front tilting end of the arc-shaped cradle 2. The first chain conveying belt 4-1 and the second chain conveying belt 4-2 form non-contact interval intersection at the lowest part of the arc-shaped cradle 2. Two groups of symmetrically arranged interlinkage belts 4 limit the arc cradle 2 to do reciprocating motion back and forth on the base 1.

The base 1 is also provided with an auxiliary track 18, the auxiliary track 18 comprises a track frame 18-1 fixed on the base 1 and a track wheel 18-2 fixed on the bracket of the arc-shaped cradle 2, and the track wheel 18-2 reciprocates on the inner side of the track frame 18-1 along with the arc-shaped cradle 2. The track of the arc-shaped cradle 2 is defined in an auxiliary way.

The front electric push rod 10, the rear electric push rod 15, the first electric push rods 7-5 and the motor 6 are controlled by a controller in the rocking chair, and a switch button matched with the controller is arranged on the chair. The reclining chair is not limited to single use and the width of the arc bar structure 2 and the seat frame 3 may be increased to make the reclining chair for two or more persons.

As shown in fig. 6, the present invention provides another embodiment, which is different from the previous embodiment in the difference of the limiting mechanism, and the limiting mechanism of this embodiment uses two sets of racks 5 capable of meshing with each other. The single pair of racks 5 includes a linear rack 5-1 and an arc rack 5-2. The linear rack 5-1 is fixed on the base 1; the arc-shaped rack 5-2 is fixed on the arc-shaped cradle 2; the linear rack 5-1 and the arc rack 5-2 are mutually meshed; due to the meshing effect of the linear rack 5-1 and the arc rack 5-2, the arc cradle 2 can only do reciprocating motion back and forth on the base 1. The other parts are consistent with the main scheme.

The above examples are only for the purpose of illustrating the idea and features of the present invention, and are intended to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, and the protection scope of the present invention is not limited to the above examples. Therefore, all changes and modifications that come within the spirit of the invention are desired to be protected.