Linkage mechanism and trolley with the linkage mechanism

Abstract

The present invention relates to the field of trolley technology, and more specifically, to a linkage mechanism and a trolley with the linkage mechanism, wherein the linkage mechanism includes an up-and-down moving mechanism, a reciprocating mechanism, a first rotating mechanism, and a second rotating mechanism, the up-and-down moving mechanism abuts against the reciprocating mechanism, the reciprocating mechanism is sleeved in the first rotating mechanism and can be extended or contracted in the first rotating mechanism, the reciprocating mechanism can limit the first rotating mechanism in the extended state, the first rotating mechanism is rotatably connected to the second rotating mechanism, and the end of the first rotating mechanism can also abut against the end of the second rotating mechanism. The present invention provides a linkage mechanism, which can be folded and stored by simply pressing down and rotating, so that the trolley with the linkage mechanism can be conveniently folded, and the wheels can be folded while the handle is folded, which is simple and convenient to operate, and greatly reduces the storage space of the trolley.

Description

Technical Field

[0001] The present invention relates to the technical field of trolleys, and more particularly to a linkage mechanism and a trolley having the linkage mechanism. Background Art

[0002] In order to save storage space when not in use, trolleys are generally designed to be foldable. However, most existing foldable trolleys can only fold the handle portion, while the wheel portion cannot be folded, resulting in the trolley still occupying a large storage space after being folded. Some trolleys with foldable handles and wheels are usually folded in steps, which is time-consuming and labor-intensive.

[0003] Chinese patent CN203793381U discloses a folding trolley with a relatively simple structure, but only the handle portion can be folded, and the wheel portion cannot be folded, so the trolley is still inconvenient to store when not in use.

[0004] Chinese patent CN210310429U discloses a wheel trolley with foldable wheels, which has a complex structure and requires many steps to fold, and is not convenient enough. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a linkage mechanism that can complete folding and storage through simple pressing and rotating actions, so that a trolley with the linkage mechanism can be easily folded, and the wheels can be folded while the handles are folded. The operation is simple and convenient, and the storage space of the trolley is greatly reduced.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A linkage device is provided, including an up and down moving mechanism, a reciprocating mechanism, a first rotating mechanism, and a second rotating mechanism. The up and down moving mechanism abuts against the reciprocating mechanism, the reciprocating mechanism is sleeved in the first rotating mechanism and can be extended or contracted in the first rotating mechanism, the reciprocating mechanism limits the first rotating mechanism when in an extended state, the first rotating mechanism is rotationally connected to the second rotating mechanism, and the end of the first rotating mechanism can also abut against the end of the second rotating mechanism to rotationally limit the second rotating mechanism; the up and down moving mechanism can cause the reciprocating mechanism to contract during the movement to release the limit on the first rotating mechanism, and the first rotating mechanism can release the limit on the second rotating mechanism when rotating, so that the second rotating mechanism moves linearly and rotates under the elastic action.

[0008] The up and down moving mechanism of the present invention can move up and down, the reciprocating mechanism can realize reciprocating motion back and forth, the first rotating mechanism can rotate, and the second rotating mechanism can realize rotation while extending with the help of elastic restoring force; in the initial state, the reciprocating mechanism is in an extended state, at this time, the end of the reciprocating mechanism is inserted into the end of the first rotating mechanism for limiting, so that the first rotating mechanism cannot rotate under the action of external force, and at this time, the second rotating mechanism is in a compressed state due to the abutment with the end of the rotating mechanism; when the up and down moving mechanism moves downward, it simultaneously pushes the reciprocating mechanism to shrink inward, thereby releasing the limit of the reciprocating mechanism on the first rotating mechanism, at this time, the first rotating mechanism can rotate, and after the first rotating mechanism rotates, the second rotating mechanism will no longer abut against the first rotating mechanism, since there is no external force restriction, the second rotating mechanism restores the extended state under the action of elasticity, and in the process of the second rotating mechanism changing from a compressed state to an extended state, it is accompanied by a rotational motion while moving linearly. The present invention can connect the up and down moving mechanism with the handle of the trolley and connect the second rotating mechanism with the wheel. The wheel can be driven to rotate synchronously by simply pressing down and rotating the handle part. The wheel can be folded while the handle is folded. The operation is simple and convenient, and no intellectual labor is required. The trolley is suitable for use by various people.

[0009] Preferably, there are two reciprocating motion mechanisms, which are symmetrically arranged on both sides of the up and down moving mechanism and both reciprocating motion mechanisms are sleeved in the first rotating mechanism; there are two second rotating mechanisms, and the two second rotating mechanisms are rotationally connected to the two ends of the first rotating mechanism respectively.

[0010] Preferably, the reciprocating motion mechanism includes a first push rod and a first spring. The first push rod abuts against the up-and-down moving mechanism, and the end of the first push rod is connected to the first spring. The first push rod can move toward the direction of the first spring under the push of the up-and-down moving mechanism to put the first spring in a compressed state.

[0011] Preferably, the first rotating mechanism includes a sleeve with a hollow cavity, a U-shaped rotating bracket, and a connecting rod. The sleeve is sleeved on the first push rod and the first spring. The U-shaped rotating bracket is installed at the end of the sleeve. The first push rod is movably connected to the U-shaped rotating bracket. The connecting rod is provided at the open end of the U-shaped rotating bracket and is rotatably connected to the U-shaped rotating bracket.

[0012] Preferably, the first rotating mechanism also includes a first connecting piece fixedly arranged on the U-shaped rotating bracket close to the end of the sleeve, and a clamping piece used to drive the first connecting piece to rotate, a first clamping groove is provided on the first connecting piece, and a second clamping groove is provided on the end of the sleeve close to the U-shaped rotating bracket, the clamping piece is provided in the first clamping groove and is rotatably connected to the first connecting piece, and a protrusion is provided on the clamping piece, and the protrusion can be inserted into the second clamping groove and clamped with the second clamping groove.

[0013] Preferably, the first connecting member is a circular ring structure with a notch on the circular ring structure, and a second connecting member is provided at the end of the sleeve, the second connecting member is located in the notch of the first connecting member and can rotate within the notch of the first connecting member; a latch pin is provided on the first push rod; when the first spring is in a compressed state, the latching member is engaged with the second slot, and when the first spring is extended, the first push rod can be pushed to move so that the latch pin can push the latching member out of the second slot.

[0014] Preferably, the second rotating mechanism includes a support rod, a first sleeve, a second spring, and a second sleeve which are movably mounted on the support rod in sequence, a ratchet is provided at the end of the first sleeve close to the second spring, and a reverse ratchet is provided at the end of the second sleeve close to the second spring, the end of the support rod is inserted into the U-shaped rotating bracket, the connecting rod is arranged through the U-shaped rotating bracket and the support rod, and when the second spring is in a compressed state, the first sleeve abuts against the end of the U-shaped rotating bracket.

[0015] The present invention also provides a trolley, comprising a handle, the linkage device as described above, and a support frame provided with at least one wheel, wherein there are two support frames, the handle is connected to the end of the linkage device close to the up and down moving mechanism, and the two support frames are respectively installed at the bottom of two second rotating mechanisms and can rotate with the second rotating mechanisms.

[0016] Preferably, the handle is a retractable structure, and when the handle is pressed downward, it can abut against the up-and-down moving mechanism and push the up-and-down moving mechanism to move downward.

[0017] Preferably, it also includes a bottom plate, which is installed above the support frame and connected to the first rotating mechanism and the two second rotating mechanisms.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The up-and-down movement of the up-and-down movement mechanism is converted into the horizontal movement of the reciprocating mechanism through the up-and-down movement of the up-and-down movement mechanism. The horizontal movement of the reciprocating mechanism controls whether to limit the first rotating mechanism. In the limited state, the U-shaped rotating bracket of the first rotating mechanism cannot rotate, and the first sleeve of the second rotating mechanism abuts against the U-shaped rotating bracket, so that the second spring is in a compressed state, but the sleeve of the first rotating mechanism can rotate; in the non-limited state, the U-shaped rotating bracket of the first rotating mechanism can rotate. After the U-shaped rotating bracket rotates relative to the connecting rod, the abutment between the U-shaped rotating bracket and the first sleeve is released, and the restoring force of the second spring pushes the first sleeve to move forward linearly while realizing synchronous rotation using the ratchet;

[0020] (2) By forming a linkage device with the up-and-down moving mechanism, the reciprocating motion mechanism, the first rotating mechanism, and the second rotating mechanism, the force of a single point of action can be transmitted to the entire device through a clever design, and the overall linkage can be achieved without acting on multiple points separately; by applying force downwards through the handle of the trolley, the limit of the reciprocating motion mechanism on the first rotating mechanism can be released while the handle is retracted, and then the wheels can be rotated and folded through the cooperation of the second rotating mechanism, so that a rotational force can be applied to the handle. When the handle is rotated, the vehicle can also be rotated and folded. The folding and storage of the entire trolley can be completed with a simple two-step operation on the handle, which is very simple, time-saving, labor-saving, and brain-saving;

[0021] (3) By setting the reciprocating mechanism and the first rotating mechanism into an active locking structure, the handle can be adjusted in angle when the trolley is in the unfolded normal use state, which is convenient for pulling or pushing the trolley and can be more labor-saving and safer. Compared with trolleys with fixed handles, the angle between the handle and the trolley loading panel is smaller. When the user pulls the trolley, the trolley loading panel is easy to rub against the user's feet, which can easily cause injuries in serious cases. Moreover, the small angle between the handle and the trolley loading panel is not conducive to the user pulling the goods. The problem can be solved by adjusting the angle of the handle as needed. Moreover, when the handle rotates, the first rotating mechanism cannot rotate due to the limiting effect of the reciprocating mechanism on the first rotating mechanism, thereby maintaining the unfolded state of the trolley. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a linkage device of the present invention;

[0023] Figure 2 An exploded diagram of a linkage device of the present invention;

[0024] Figure 3 It is a structural schematic diagram of a reciprocating motion mechanism;

[0025] Figure 4 is a schematic structural diagram of a sleeve, a first connecting member and a second connecting member;

[0026] Figure 5 for Figure 4 Another perspective structural diagram of;

[0027] Figure 6 is a structural schematic diagram of a first connecting member;

[0028] Figure 7 It is a structural schematic diagram of a card connector;

[0029] Figure 8 It is a structural schematic diagram of a trolley in a first open state of the present invention;

[0030] Fig. 9 It is a structural schematic diagram of a trolley in a second open state of the present invention;

[0031] Fig.10 It is a structural schematic diagram of a trolley in a folded state from a first viewing angle of the present invention;

[0032] Fig.11 It is a structural schematic diagram of a trolley in a folded state according to the present invention from a second viewing angle;

[0033] Fig.12 It is a structural schematic diagram of a trolley in a folded state of the present invention from a third viewing angle with a single-side U-shaped rotating bracket removed;

[0034] Fig.13 It is a cross-sectional view when the handle is in a vertical direction;

[0035] Fig.14 for Fig.13 Exploded diagram.

[0036] The illustrations are as follows:

[0037] 1. Up and down moving mechanism; 11. Second push rod; 12. Push block; 2. Reciprocating mechanism; 21. First push rod; 211. Pin; 22. Sliding block; 23. First spring; 3. First rotating mechanism; 31. Sleeve; 311. Second slot; 32. U-shaped rotating bracket; 33. Connecting rod; 34. First connecting member; 341. First slot; 35. Connecting member; 351. Protrusion; 36. Second connecting member; 4. Second rotating member Rotating mechanism; 41, supporting rod; 42, first sleeve; 421, ratchet; 43, second spring; 44, second sleeve; 441, reverse ratchet; 45, third sleeve; 101, linkage; 102, handle; 1021, handle; 1022, pull rod; 1023, outer rod; 1024, inner rod; 1025, transmission rod; 1026, elastic bayonet; 103, supporting frame; 104, wheel; 105, bottom plate. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with specific implementation methods. The accompanying drawings are only used for exemplary descriptions and are only schematic diagrams, not actual drawings, and cannot be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0039] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0040] Example

[0041] like Figures 1 to 7 The figure shows an embodiment of a linkage device of the present invention, comprising an up-and-down moving mechanism 1, a reciprocating mechanism 2, a first rotating mechanism 3, and a second rotating mechanism 4. The up-and-down moving mechanism 1 is in contact with the reciprocating mechanism 2. The reciprocating mechanism 2 is sleeved in the first rotating mechanism 3 and can be extended or contracted in the first rotating mechanism 3. The reciprocating mechanism 2 can limit the first rotating mechanism 3 when in the extended state. The first rotating mechanism 3 is rotationally connected to the second rotating mechanism 4, and the end of the first rotating mechanism 3 can also be in contact with the end of the second rotating mechanism 4 to rotationally limit the second rotating mechanism 4. The up-and-down moving mechanism 1 can cause the reciprocating mechanism 2 to contract during the movement to release the limit on the first rotating mechanism 3. When the first rotating mechanism 3 rotates, it can release the limit on the second rotating mechanism 4 so that the second rotating mechanism 4 moves linearly and rotates under the action of elasticity.

[0042] Furthermore, if Figure 3 As shown, there are two reciprocating mechanisms 2, which are symmetrically arranged on both sides of the up and down moving mechanism 1, and the two reciprocating mechanisms 2 are both sleeved in the first rotating mechanism 3; there are two second rotating mechanisms 4, and the two second rotating mechanisms 4 are rotatably connected to the two ends of the first rotating mechanism 3 respectively.

[0043] Specifically, if Figure 2As shown, the two second rotating mechanisms 4 are respectively used to connect with the wheels 104 on both sides of the trolley, so as to facilitate driving the wheels 104 to fold, and the two second rotating mechanisms 4 are respectively abutted against the two ends of the first rotating mechanism 3, and the reciprocating mechanisms 2 on both sides are driven to shrink toward the middle through an up and down moving mechanism 1 at the same time, so as to release the limit of the reciprocating mechanism 2 on the end of the first rotating mechanism 3, so that the second rotating mechanisms 4 on both sides can rotate subsequently. Here, the two symmetrically arranged second rotating mechanisms 4 rotate in different directions when changing from a compressed state to an extended state, and both rotate in opposite directions, that is, each rotates toward the middle, so that the wheels 104 connected thereto can be folded inwards, further saving storage space.

[0044] Furthermore, the reciprocating motion mechanism 2 includes a first push rod 21 and a first spring 23. The first push rod 21 abuts against the up-and-down moving mechanism 1, and the end of the first push rod 21 is connected to the first spring 23. The first push rod 21 can move toward the first spring 23 under the push of the up-and-down moving mechanism 1 to put the first spring 23 in a compressed state.

[0045] Preferably, the two reciprocating mechanisms 2 distributed on both sides of the up and down moving mechanism 1 can share a first spring 23, and the first push rod 21 abuts against the up and down moving mechanism 1. During the downward movement of the up and down moving mechanism 1, the sliding block 22 is pushed to move in the direction of compressing the first spring 23. Specifically, the part in which the first push rod 21 abuts against the up and down moving mechanism 1 can be a wedge-shaped or triangular structure, and the structure of the end of the up and down moving mechanism 1 that contacts the first push rod 21 can be the same as the structure of the first push rod 21, but is set in reverse, so that the surface of the up and down moving mechanism 1 can be completely in contact with the surface of the wedge-shaped or triangular structure of the first push rod 21 when moving downward, thereby exerting a better force and driving the first push rod 21 to move; at the same time, the first push rod 21 drives the first push rod 21 to retract, so that the first push rod 21 releases the limit on the first rotating mechanism 3, and the first rotating mechanism 3 can rotate under the action of external force after the limit is released. Of course, a slider 22 can also be set at the place where the first push rod 21 contacts the up-and-down moving mechanism 1. One end of the slider 22 is connected to one end of the first push rod 21, and the other end is connected to the first spring 23. The top of the slider 22 abuts against the up-and-down moving mechanism 1. The slider 22 can be a wedge-shaped or triangular structure. When the up-and-down moving mechanism 1 moves downward, the slider 22 drives the first push rod 21 to move in the direction of compressing the first spring 23, so that the first push rod 21 releases the limit on the first rotating mechanism 3.

[0046] Furthermore, the first rotating mechanism 3 includes a sleeve 31 with a hollow cavity, a U-shaped rotating bracket 32, and a connecting rod 33. The sleeve 31 is sleeved on the first push rod 21 and the first spring 23 of the slider. The U-shaped rotating bracket 32 ​​is installed at the end of the sleeve 31. The first push rod 21 is movably connected to the U-shaped rotating bracket 32. The connecting rod 33 is provided at the open end of the U-shaped rotating bracket 32 ​​and is rotatably connected to the U-shaped rotating bracket 32.

[0047] Specifically, there are two U-shaped rotating brackets 32, which are respectively arranged at the two ends of the sleeve 31. The two ends of the connecting rod 33 are inserted into the two U-shaped rotating brackets 32 symmetrically arranged about the reciprocating motion mechanism 2, and the connecting rod 33 can act as a rotating axis when the first rotating mechanism 3 rotates. When the first spring 23 is in an extended state, the first push rod 21 is inserted into the U-shaped rotating bracket 32. Under the limiting action of the first push rod 21, the U-shaped rotating bracket 32 ​​cannot rotate around the connecting rod 33. When the first spring 23 is in a compressed state, the first push rod 21 retracts and exits the U-shaped rotating bracket 32, that is, the limiting of the U-shaped rotating bracket 32 ​​is released. At this time, an external force is applied to the sleeve 31, and the sleeve 31 can drive the U-shaped rotating brackets 32 at both ends to rotate around the connecting rod 33.

[0048] Furthermore, if Figures 4 to 7 As shown, the first rotating mechanism 3 also includes a first connecting member 34 fixedly arranged on the U-shaped rotating bracket 32 ​​near the end of the sleeve 31, and a clamping member 35 for driving the first connecting member 34 to rotate. A first clamping groove 341 is provided on the first connecting member 34, and a second clamping groove 311 is provided at the end of the sleeve 31 near the U-shaped rotating bracket 32. The clamping member 35 is arranged in the first clamping groove 341 and is rotatably connected to the first connecting member 34. A protrusion 351 is provided on the clamping member 35, and the protrusion 351 can be inserted into the second clamping groove 311 and clamped with the second clamping groove 311.

[0049] Specifically, the clamping member 35 is arranged in the first clamping groove 341 in the first connecting member 34 and can be rotatably connected to the first connecting member 34. The protrusion 351 of the clamping member 35 is inserted into the second clamping groove 311 of the sleeve 31 so that when the sleeve 31 rotates, the clamping member 35 can be driven, and then the first connecting member 34 is driven to cause the U-shaped rotating bracket 32 ​​to rotate, thereby realizing the linkage between the sleeve 31 and the U-shaped rotating bracket 32. Here, the sleeve 31 and the U-shaped rotating bracket 32 ​​are not fixedly connected, but are connected in a movable connection manner, so that the sleeve 31 and the U-shaped rotating bracket 32 ​​can have two different states. One state is that the sleeve 31 and the U-shaped rotating bracket 32 ​​are not connected. At this time, the rotation of the sleeve 31 will not drive the U-shaped rotating bracket 32 ​​to rotate, and the sleeve 31 can be connected to the handle 102 of the trolley, so that the handle 102 can be adjusted in angle when the trolley is in normal use; the other state is that the sleeve 31 and the U-shaped rotating bracket 32 ​​are connected. At this time, the rotation of the sleeve 31 can drive the U-shaped rotating bracket 32 ​​to rotate, realizing the function of linkage folding; this is one of the important invention points of the present invention. The connection between the sleeve 31 and the U-shaped rotating bracket 32 ​​can be realized as needed.

[0050] Furthermore, the first connecting member 34 is a circular ring structure and is provided with a notch in the circular ring structure, and a second connecting member 36 is provided at the end of the sleeve 31, and the second connecting member 36 is located in the notch of the first connecting member 34 and can rotate within the notch; a latch 211 is provided on the first push rod 21; when the first spring 23 is in a compressed state, the clamping member 35 is clamped with the second clamping groove 311, and when the first spring 23 is extended, the first push rod 21 can be pushed to move so that the latching pin 211 pushes the clamping member 35 out of the second clamping groove 311.

[0051] Specifically, the second connecting member 36 provided at the end of the sleeve 31 is in active contact with the first connecting member 34. The notch on the first connecting member 34 is provided to limit the rotation of the sleeve 31 when the first push rod 21 retracts under the drive of the first spring 23 to release the limit on the U-shaped rotating bracket 32. The angular range corresponding to the gap between the notch and the second connecting member 36 is the angular range in which the sleeve 31 can rotate. The cross-section of the portion of the second connecting member 36 inserted into the notch of the first connecting member 34 is a portion of a circular ring. The notch is usually set to 1 / 4 circle, that is, 90 degrees, and the circular ring angle corresponding to the portion of the second connecting member 34 inserted into the notch is 30 degrees. In this way, the sleeve 31 can be adjusted within the range of 0 to 60 degrees, which is sufficient to meet the angle adjustment requirements of the handle 102 when the trolley is in use. Of course, the size of the notch can be set according to the needs of the user. Within the scope of cognition of those skilled in the art, the notch and the corresponding portion of the second connecting member 36 in the notch can also be set to other angles. The arrangement of the latch 211 on the first push rod 21 can control whether the clamping member 35 can realize the connection between the sleeve 31 and the first connecting member 34. When the first spring 23 is in a compressed state, at this time, it is also the time when the first push rod 21 is released from the limit of the U-shaped rotating bracket 32, the protrusion 351 of the clamping member 35 is clamped in the second clamping groove 311, so that the clamping member 35 and the sleeve 31 are clamped. At this time, the linked rotation of the U-shaped rotating bracket 32 ​​can be realized by rotating the sleeve 31; and when the first spring 23 is released from the compressed state and begins to stretch, it can push the first push rod 21 to move, so that the latch 211 can release the clamping member 35 from the second clamping groove. The first push rod 21 is pushed out from the center of the sleeve 311 to release the clamping relationship between the sleeve 31 and the clamping member 35. At the same time, the first push rod 21 is also inserted into the U-shaped rotating bracket 32 ​​to limit the U-shaped rotating bracket 32. At this time, when the sleeve 31 is rotated, even if the second connecting member 36 and the first connecting member 34 will abut against the first connecting member 34 at the extreme position, the U-shaped rotating bracket 32 ​​will not rotate therewith because the U-shaped rotating bracket 32 ​​is limited. Therefore, the rotation of the sleeve 31 will not drive the U-shaped rotating bracket 32 ​​to rotate. The limiting effect of the first push rod 21 is the key to keeping the U-shaped rotating bracket 32 ​​in its original state. When the trolley is in use, the handle 102 can be adjusted without affecting the normal operation of the wheel 104 end.

[0052] Furthermore, if Figure 2As shown, the second rotating mechanism 4 includes a support rod 41, a first sleeve 42, a second spring 43, and a second sleeve 44 which are movably sleeved on the support rod 41 in sequence, a ratchet 421 is provided at the end of the first sleeve 42 close to the second spring 43, and a reverse ratchet 441 is provided at the end of the second sleeve 44 close to the second spring 43. The end of the support rod 41 is inserted into the U-shaped rotating bracket 32, and the connecting rod 33 is arranged through the U-shaped rotating bracket 32 ​​and the support rod 41. When the second spring 43 is in a compressed state, one end of the first sleeve 42 abuts against the end of the U-shaped rotating bracket 32, and the other end abuts against the second sleeve 44. The ratchet 421 of the first sleeve 42 and the reverse ratchet 441 of the second sleeve 44 cooperate with each other.

[0053] The ratchet teeth 421 of the first sleeve 42 cooperate with the reverse ratchet teeth 441 of the second sleeve 44 to form a structure that can be converted into rotation by linear reciprocating movement. The second spring 43 is arranged between the first sleeve 42 and the second sleeve 44, and the restoring force of the spring is used to promote the linear movement of the first sleeve 42, so that the first sleeve 42 rotates while moving linearly; specifically, when the U-shaped rotating bracket 32 ​​abuts against the first sleeve 42, the second spring 43 is in a compressed state. After the U-shaped rotating bracket 32 ​​is driven by the sleeve 31 to rotate relative to the connecting rod 33, the U-shaped rotating bracket 32 ​​no longer abuts against the first sleeve 42. At this time, under the push of the restoring force of the second spring 43, the first sleeve 42 moves forward while rotating itself, and the first sleeve 42 can be connected to the wheel 104, and the first sleeve 42 can drive the wheel 104 to rotate to achieve folding and storage.

[0054] Furthermore, the up and down moving mechanism 1 includes a second push rod 11 and a push block 12. The push block 12 is arranged at the bottom of the second push rod 11 and a wedge-shaped or triangular structure that cooperates with the first push rod 21 is provided at the contact position between the bottom of the push block 12 and the first push rod 21, but is arranged in the opposite direction to the wedge-shaped or triangular structure on the first push rod 21. When the second push rod 11 pushes the push block 12 to move downward, the bottom of the push block 12 abuts against the first push rod 21 to compress the first spring 23.

[0055] like Figures 8 to 14 As shown, the present invention also provides a trolley with the above-mentioned linkage device, including a handle 102, a linkage device 101 as mentioned above, and a support frame 103 provided with at least one wheel 104, there are two support frames 103, the handle 102 is connected to the end of the linkage device 101 close to the up and down moving mechanism 1, and the two support frames 103 are respectively installed at the bottom of the two second rotating mechanisms 4 and can rotate with the second rotating mechanisms 4.

[0056] Preferably, if Fig.13As shown, the handle 102 is a retractable structure. When the handle 102 is pressed down, it can contact with the up-and-down moving mechanism 1 and push the up-and-down moving mechanism 1 to move downward. The handle 102 includes a handle 1021 and a pull rod 1022. The handle 1021 is arranged at the top of the pull rod 1022 to facilitate holding and applying force to the cart. Preferably, the handle 1021 is annular; the pull rod 1022 includes an outer rod 1023 and an inner rod 1024 with a hollow cavity, and a transmission rod 1025 arranged at the bottom of the outer rod 1023. The top of the inner rod 1024 is connected to the handle 1021, and the inner rod 1024 is nested in the outer rod 1023. The outer rod 1023 and the inner rod 1024 are connected by an elastic latch 1026. The elastic latch 1026 also plays a limiting role. After pressing the elastic latch 1026 inward, the handle 1021 can be forced downward to retract the inner rod 1024 into the outer rod 1023. When the inner rod 1024 moves to the bottom of the outer rod 1023, it can be connected with the up-and-down moving mechanism 1 of the linkage device 101. Specifically, the second push rod 11 is inserted into the bottom of the inner rod 1024 to make the inner rod 1024 abut against the push block 12. The inner rod 1024 pushes the push block 12 to move downward and then realizes linkage with the first push rod 21. The transmission rod 1025 is also provided with a hollow cavity. The transmission rod 1025 is sleeved on the outside of the sleeve 31 of the linkage device 101. Therefore, by applying force to the handle 1021 to rotate the pull rod 1022, the transmission rod 1025 can be driven to rotate the sleeve 31.

[0057] Preferably, a groove is provided on the support frame 103, and a wheel 104 is provided at the bottom of the support frame 103. One support frame 103 is connected to at least two wheels 104. If used on a larger cart and the support frame 103 is longer, multiple wheels 104 can also be connected to the bottom of one support frame 103. On the one hand, the wheel 104 can provide support for the cart, and on the other hand, the wheel 104 can facilitate the movement of the cart; preferably, the wheel 104 is a universal wheel. The groove of the support frame 103 cooperates with the second rotating mechanism 4 of the linkage device 101, and the first sleeve 42, the second spring 43, the second sleeve 44, and the support rod 41 are all placed in the groove of the support frame 103, and then the first sleeve 42 is connected to the support frame 103 by screws, and the second sleeve 44 is connected to the support rod 41. Preferably, a third sleeve 45 is provided at the end of the support rod 41 away from the first sleeve 42, and the third sleeve 45 is also placed in the groove of the support frame 103. The screws pass through the support frame 103 and the third sleeve 45 to connect the third sleeve 45 to the support frame 103. In this way, when the U-shaped rotating bracket 32 ​​is no longer in contact with the first sleeve 42, the first sleeve 42 moves forward and rotates while being pushed by the restoring force of the second spring 43, driving the support frame 103 and the vehicle to fold toward the middle of the trolley to complete the storage action. The third sleeve 45 rotates with the support frame 103 relative to the support rod 41 when the support frame 103 rotates, so that the force of the entire support frame 103 is balanced when rotating, and the wheels 104 at different positions of the support rod 41 can rotate to complete folding and storage. In order to make the front and rear wheels of the trolley more balanced and make the structure of the entire trolley more stable, a connecting rod 33 can be set at the end of the support rod 41 away from the U-shaped rotating bracket 32, assuming that it is between the two support rods 41. In this way, the front and rear connecting rods 33 and the left and right support rods 41 together form a relatively stable square structure, which can prevent the entire trolley from being easily deformed.

[0058] Preferably, it further comprises a bottom plate 105 , which is installed above the support frame 103 and connected to the first rotating mechanism 3 and the two second rotating mechanisms 4 .

[0059] The bottom 105 is used to provide support for items placed on the trolley. Specifically, both ends of the bottom plate 105 are welded or buckled to the two connecting rods 33, and both sides of the bottom plate 105 are welded or buckled to the two supporting rods 41. It is preferably connected by buckling to form a detachable connection relationship, which is convenient for replacement and disassembly.

[0060] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A linkage device, characterized in that: The invention comprises an up-and-down moving mechanism (1), a reciprocating mechanism (2), a first rotating mechanism (3), and a second rotating mechanism (4); the up-and-down moving mechanism (1) is in contact with the reciprocating mechanism (2); the reciprocating mechanism (2) is sleeved in the first rotating mechanism (3) and can be extended or contracted in the first rotating mechanism (3); the reciprocating mechanism (2) can limit the first rotating mechanism (3) when in an extended state; the first rotating mechanism (3) is rotationally connected to the second rotating mechanism (4); the end of the first rotating mechanism (3) is also in contact with the end of the second rotating mechanism (4) and rotationally limits the second rotating mechanism (4); the up-and-down moving mechanism (1) can cause the reciprocating mechanism (2) to contract during movement to release the limit on the first rotating mechanism (3); the first rotating mechanism (3) can release the limit on the second rotating mechanism (4) when rotating, so that the second rotating mechanism (4) moves linearly and rotates under the action of elasticity. The reciprocating mechanism (2) comprises a first push rod (21) and a first spring (23), wherein the first push rod (21) is in contact with the up-and-down moving mechanism (1), and an end of the first push rod (21) is connected to the first spring (23), and the first push rod (21) can move in the direction of the first spring (23) under the push of the up-and-down moving mechanism (1) to put the first spring (23) in a compressed state; the first rotating mechanism (3) comprises a sleeve (31) provided with a hollow cavity, a U-shaped rotating bracket (32), and a connecting rod (33), wherein the sleeve (31) is sleeved on the outside of the first push rod (21) and the first spring (23), the U-shaped rotating bracket (32) is mounted on an end of the sleeve (31), the first push rod (21) is movably connected to the U-shaped rotating bracket (32), and the connecting rod (33) is provided at an open end of the U-shaped rotating bracket (32) and is rotatably connected to the U-shaped rotating bracket (32).

2. The linkage device according to claim 1, characterized in that: The first rotating mechanism (3) further comprises a first connecting member (34) fixedly arranged at an end of the U-shaped rotating bracket (32) close to the sleeve (31), and a clamping member (35) for driving the first connecting member (34) to rotate; a first clamping groove (341) is provided on the first connecting member (34); a second clamping groove (311) is provided on an end of the sleeve (31) close to the U-shaped rotating bracket (32); the clamping member (35) is arranged in the first clamping groove (341) and is rotatably connected to the first connecting member (34); a protrusion (351) is provided on the clamping member (35); the protrusion (351) can be inserted into the second clamping groove (311) and clamped with the second clamping groove (311).

3. The linkage device according to claim 2, characterized in that: The first connecting member (34) is a circular ring structure and is provided with a notch. A second connecting member (36) is provided at the end of the sleeve (31). The end of the second connecting member (36) is located in the notch of the first connecting member (34) and can rotate within the notch of the first connecting member (34). A latch pin (211) is provided on the first push rod (21). When the first spring (23) is in a compressed state, the latching member (35) is latched with the second latching groove (311). When the first spring (23) is extended, the first push rod (21) can be pushed to move so that the latch pin (211) is pushed out of the second latching groove (311) to eject the latching member (35).

4. The linkage device according to any one of claims 1 to 3, characterized in that: The second rotating mechanism (4) comprises a support rod (41), a first sleeve (42), a second spring (43), and a second sleeve (44) which are movably sleeved on the support rod (41) in sequence; a ratchet (421) is provided at an end of the first sleeve (42) close to the second spring (43); and a reverse ratchet (441) is provided at an end of the second sleeve (44) close to the second spring (43); an end of the support rod (41) is inserted into the U-shaped rotating bracket (32); the connecting rod (33) is arranged to pass through the U-shaped rotating bracket (32) and the support rod (41); and when the second spring (43) is in a compressed state, the first sleeve (42) abuts against the end of the U-shaped rotating bracket (32).

5. A trolley, characterized in that: The invention comprises a handle (102), a linkage device (101) as claimed in any one of claims 1 to 4, and a support frame (103) provided with at least one wheel (104), wherein the support frames (103) are two, the handle (102) is connected to the end of the linkage device (101) close to the up-and-down moving mechanism (1), and the two support frames (103) are respectively mounted at the bottom of two second rotating mechanisms (4) and can rotate with the second rotating mechanisms (4).

6. The trolley according to claim 5, characterized in that: The handle (102) is a retractable structure, and when pressed downward, the handle (102) can abut against the up-and-down moving mechanism (1) and push the up-and-down moving mechanism (1) to move downward.

7. The trolley according to claim 5 or 6, characterized in that: It also comprises a bottom plate (105), wherein the bottom plate (105) is installed above the support frame (103) and is connected to the first rotating mechanism (3) and the two second rotating mechanisms (4).

Images