A linkage locking device

Abstract

A linked locking device comprises a frame and at least two brake assemblies for braking travel wheels. The brake assemblies include brake cams and brake members slidably disposed relative to the travel wheels. A drive rod is disposed between the two brake assemblies, and the drive rod is connected in series with the two brake cams to form a two-wheel brake module. Rotation of the drive rod causes the brake cams in the two brake assemblies to rotate simultaneously, driving the two brake members to respectively lock or disengage the two travel wheels. The present invention is characterized by ease of operation and excellent flexibility.

Description

Technical Field

[0001] The invention relates to a mechanical linkage structure, in particular to a linkage locking device. Background Art

[0002] Typically, four running wheels arranged in a rectangular shape are installed at the lower end of a movable device such as a cart or a movable bed, so that an operator can move the movable device easily. The running wheels can be straight wheels or universal wheels.

[0003] In the prior art, each running wheel is equipped with a corresponding brake structure, and at least two running wheels need to be braked to achieve the fixation and position control of the movable device. Therefore, during the braking process of the movable device, the operator needs to perform the braking action at least twice, which is inconvenient to a certain extent. Summary of the Invention

[0004] The present invention mainly solves the technical problem in the prior art of inconvenient operation caused by multiple braking actions, and provides a linkage locking device.

[0005] In order to solve the above technical problems and achieve the above invention objectives, the present invention provides a linkage locking device, comprising a frame and at least two groups of brake assemblies for braking the traveling wheels, the brake assemblies comprising brake cams and brake members slidingly arranged relative to the traveling wheels, a driving rod is provided between the two groups of the brake assemblies, the driving rod is connected in series with the two brake cams to form a two-wheel brake module; under the rotation of the driving rod, the brake cams in the two brake assemblies rotate simultaneously to drive the two brake members to lock or disengage the two traveling wheels respectively.

[0006] In one embodiment, the brake assembly is provided in four groups, and the drive rods are provided in two groups and are arranged in parallel.

[0007] In one embodiment, a linkage assembly is provided between the two driving rods. Under the transmission of the linkage assembly, the two driving rods rotate synchronously. The driving rods and the linkage assembly constitute a four-wheel brake module.

[0008] In one embodiment, the brake assemblies are provided in four groups, the drive rods are provided in two groups, and the drive rods are located between two diagonally arranged brake assemblies.

[0009] In one embodiment, when the traveling wheel is a universal wheel, a locking assembly is provided on the frame, and the locking assembly includes a rotatable locking cam and two positioning pins relatively arranged on both sides of the locking cam. A positioning flange for fixedly connecting the traveling wheel is rotatably provided on the frame, and when the locking cam rotates, the positioning pin is used to lock or disengage from the positioning flange to achieve locking or unlocking of the rotation direction of the traveling wheel.

[0010] In one embodiment, the locking assembly is provided with two groups and arranged opposite to each other, a two-way straight-moving linkage rod is rotatably connected to the frame, the two-way straight-moving linkage rod is connected in series with two locking cams, and the projections of the two locking cams along the axial direction of the two-way straight-moving linkage rod do not overlap.

[0011] In one embodiment, the locking protrusion includes a locking base and two locking protrusions arranged opposite to the locking base, each of the two locking protrusions is provided with a first limiting groove for accommodating the end of the positioning pin, and the two first limiting grooves are arranged opposite to each other.

[0012] In one embodiment, the locking base is provided with two second limiting grooves for accommodating the ends of the positioning pins, the two second limiting grooves are arranged opposite to each other, and the second limiting grooves of the two locking cams coincide with each other in their axial projection along the bidirectional straight-moving linkage rod.

[0013] In one embodiment, the outer peripheral surface of the positioning pin is provided with a first abutment portion, the frame includes an abutment surface located on the side of the first abutment portion away from the locking cam, the positioning pin passes through the abutment surface, and a first elastic member is provided between the abutment surface and the first abutment portion, and the first elastic member is used to push the positioning pin to abut against the locking cam.

[0014] In one embodiment, the positioning pin includes a first pin shaft for abutting the outer circumference of the locking cam and a second pin shaft for abutting the positioning flange. The first pin shaft is fixedly connected to a fixing seat, and the second pin shaft is axially slidably connected to the fixing seat. The outer circumference of the second pin shaft is provided with a second abutting portion. A second elastic member is provided between the second abutting portion and the fixing seat. The second elastic member is used to push the second pin shaft to abut the positioning flange. Compared with the prior art, the linkage locking device of the present invention has the following advantages:

[0015] 1. By providing a driving rod that connects the brake cams of any two sets of brake assemblies, the driving rod can be rotated to simultaneously drive the two brake cams to rotate, thereby braking the two travel wheels. The operator only needs to perform a single braking action to complete the limit and fixation of the movable device, reducing the number of operating steps in the braking process and improving operational convenience;

[0016] 2. By setting up four sets of brake assemblies and two parallel drive rods, the brake assemblies are linked in pairs. The operator can fix the movable device by turning any drive rod, further improving the convenience of operation;

[0017] 3. By setting up a linkage assembly, when the operator rotates one drive rod, the other drive rod will rotate synchronously, causing all four wheels to brake simultaneously. Compared with the braking method of two wheels, this method is conducive to increasing the resistance to pushing or pulling the movable device, thereby improving the limiting stability of the movable device;

[0018] 4. Since the drive rods are arranged between the two diagonally arranged brake assemblies, the two drive rods intersect, which has the same effect as the solution of setting the two drive rods in parallel. The operator can fix the movable device by turning either drive rod.

[0019] 5. By providing a locking assembly and rotating the locking cam, the two positioning pins can be locked or disengaged from the positioning flange, thereby locking or unlocking the rotation direction of the travel wheels. Since it is difficult for a single person to push or pull the movable device on one side when the directions of the four travel wheels are not locked, the operator can use the above structure to lock the direction of the two travel wheels on one side, making it easier for the operator to push or pull the movable device.

[0020] 6. By providing a bidirectional straight-moving linkage and with the two locking cams projected axially so that their projections do not overlap, when the locating pins of one set of locking assemblies lock the locating flange on one side, the locating pins of the other set of locking assemblies disengage from the locating flange on the corresponding side. This means that the two running wheels on one side are locked in direction, while the two running wheels on the other side are unlocked. This improves the convenience of single-person operation while ensuring that the mobile device can steer.

[0021] 7. By providing the first limiting groove, the first end of the positioning pin is prevented from sliding out of the locking protrusion as much as possible, which is conducive to maintaining the direction of the running wheel on this side in a locked state;

[0022] 8. By providing the second limiting grooves, when the two positioning pins on one side abut against the two second limiting grooves respectively, the positioning pin on the other side also abuts against the second limiting groove, and the directions of the four running wheels on both sides are unlocked, thereby improving the movement flexibility of the mobile device to meet actual operational needs;

[0023] 9. By providing a first elastic member, the positioning pin is pressed against the locking cam under the elastic force of the first elastic member, and the positioning pin and the locking cam are kept in contact, which is conducive to locking the rotation direction of the running wheel through the locking cam;

[0024] 10. By providing a fixing seat, a second elastic member, and a second pin, when the first pin abuts against the locking protrusion, the second pin, pushed by the second elastic member, has a movement tendency to lock the positioning flange, thereby achieving a locking action on the positioning flange;

[0025] Therefore, the present invention has the characteristics of easy operation, good flexibility, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Attachment Figure 1 is a top view of the present invention;

[0027] Attachment Figure 2 is a cross-sectional view of the present invention;

[0028] Attachment Figure 3 It is a fracture schematic diagram of the present invention;

[0029] Attachment Figure 4 It is attached Figure 2 A schematic diagram of the structure of the locking component;

[0030] Attachment Figure 5 It is attached Figure 4 Schematic diagram of the structure of the locking cam;

[0031] Attachment Figure 6 It is attached Figure 2 Schematic diagram of part of the structure at the middle traveling wheel.

[0032] Explanation of the numbers in the figure: 1. Frame; 11. Control box; 12. Support seat; 121. Horizontal plate; 122. Vertical plate; 124. Abutment surface; 13. Mounting shaft seat; 131. Threaded hole; 14. Steering shaft sleeve; 15. Centripetal bearing; 16. Positioning flange; 161. Limiting groove; 17. Thrust bearing; 18. Sliding shaft seat; 181. Fastening bolt; 182. Sliding channel; 2. Brake assembly; 21. Brake cam; 211. Brake base; 212. Brake cam; 22. Brake member; 221. Brake push rod; 222. Friction block; 3. Linkage assembly; 31. Drive rod; 311. Brake Vehicle pedal; 32. Brake linkage rod; 33. Connecting swing arm; 4. Travel wheel; 41. Roller; 42. Bracket; 5. Locking assembly; 51. Locking cam; 511. Locking base; 512. Locking protrusion; 513. First limiting groove; 514. Second limiting groove; 515. Third limiting groove; 52. Positioning pin; 521. First pin shaft; 522. Second pin shaft; 523. First abutting part; 524. First elastic member; 525. Second abutting part; 526. Second elastic member; 53. Two-way straight-moving linkage rod; 531. Straight-moving locking pedal; 54. Fixed seat; 541. Retaining spring. DETAILED DESCRIPTION

[0033] In order to make the purposes, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0034] Example 1:

[0035] Figure 1 is a top view of the present invention; Figure 2 It is a cross-sectional view of the present invention.

[0036] Reference Figure 1 and Figure 2 , a linkage locking device includes a frame 1 and at least two groups of brake assemblies 2 for braking the running wheels 4, and each group of brake assemblies 2 includes a brake cam 21 and a brake member 22. Under the rotation of the brake cam 21, the brake member 22 is used to lock or disengage the running wheel 4, thereby realizing whether the running wheel 4 is braked. A driving rod 31 is provided between the two groups of brake assemblies 2, and the driving rod 31 is connected in series with the brake cams 21 in the two groups of brake assemblies 2, thereby forming a two-wheel brake module. The embodiment of the present invention aims to provide a driving rod 31 so that the two brake cams 21 rotate synchronously, so that the two brake members 22 brake the two running wheels 4 respectively, and the operator only needs to perform a braking action once to complete the limiting and fixing of the movable device, thereby reducing the operating steps of the braking process and improving the convenience of operation.

[0037] The present invention is primarily directed to a mobile device equipped with four running wheels 4. These four running wheels 4 are mounted at the lower end of a frame 1, which is mounted at the lower end of the mobile device. The four running wheels 4 are typically arranged in a rectangular array. The mobile device can be a cart, a medical transfer bed, or the like. The running wheels 4 can be straight or universal. In the present invention, the running wheels 4 are universal.

[0038] In the embodiment of the present invention, there are four sets of brake assemblies 2 and two drive rods 31. The four sets of brake assemblies 2 correspond to the four running wheels 4 one by one. The drive rods 31 are arranged between two adjacent sets of brake assemblies 2, that is, the two drive rods 31 are arranged in parallel. The drive rod 31 is connected to the frame 1 by rotating around its own axis. A brake pedal 311 is provided at one end of the drive rod 31. The brake cam 21 includes a cylindrical brake base 211 and a brake protrusion 212 fixedly provided on the outer wall of the brake base 211. The brake base 211 and the brake protrusion 212 are integrally formed. The brake cams 21 in the two adjacent sets of brake assemblies 2 are clamped to the outer circumferential surface of the drive rod 31. The two brake cams 21 are arranged near the two ends of the drive rod 31, and the projections of the two brake cams 21 along the axial direction of the drive rod 31 coincide. That is, the two running wheels 4 on one side can be braked simultaneously by rotating the drive rod 31.

[0039] After the connection is completed, the brake cam 21 and the drive rod 31 do not have the freedom of relative movement. Therefore, the connection method can be welding, pin fixing, etc., and the embodiment of the present invention does not impose specific restrictions on this. The brake component 22 includes a brake push rod 221 that is slidably connected to the frame 1 in the vertical direction and a friction block 222 installed at the lower end of the brake push rod 221. The brake push rod 221 is provided with a coil spring (not shown in the figure), so that the brake push rod 221 abuts against the outer peripheral surface of the brake cam 21 by means of elastic force. The friction block 222 needs to be formed by processing a material with a large friction coefficient. It can be an asbestos friction material, a semi-metallic friction material, or a non-asbestos mixed fiber friction material. The embodiment of the present invention does not impose any restrictions on this. It is understood that the sliding connection direction of the brake component 22 and the frame 1 can be vertical or in other directions.

[0040] When braking, the operator steps on the brake pedal 311, the driving rod 31 and the two brake cams 21 rotate synchronously, and the upper end of the brake push rod 221 moves from the brake base 211 of the brake cam 21 to the brake protrusion 212, so that the brake push rod 221 slides downward, and the friction block 222 at the lower end of the brake push rod 221 abuts against the outer peripheral surface of the running wheel 4. The running wheel 4 is subjected to the dynamic friction force exerted by the friction block 222 and gradually stops rotating, thereby completing the braking process of the two running wheels 4 on the same side.

[0041] Figure 3 It is a fracture diagram of the present invention.

[0042] Reference Figure 1 and Figure 3A linkage assembly 3 is provided between the two drive rods 31. The linkage assembly 3 includes a brake linkage rod 32 and two connecting swing arms 33 respectively hinged at both ends of the brake linkage rod 32. The brake linkage rod 32 and the drive rod 31 constitute a four-wheel brake module. The end of the connecting swing arm 33 away from the brake linkage rod 32 is sleeved on the outer peripheral surface of the drive rod 31. The connecting swing arm 33 and the drive rod 31 are clamped together. The two do not have the freedom of relative rotation. The present invention does not limit the specific clamping method. When one of the drive rods 31 is rotated, the other drive rod 31 is rotated by the same angle under the transmission of the brake linkage rod 32 and the connecting swing arm 33. Therefore, under the linkage action of the brake linkage rod 32 and the connecting swing arm 33, the operator steps on any one of the brake pedals 311, thereby realizing the synchronous rotation of the two drive rods 31, so that the four running wheels 4 are braked at the same time. It is easy to understand that the linkage assembly 3 can also be other transmission structures, such as the ends of the drive rod 31 and the brake linkage rod 32 are connected by bevel gear meshing, so that the two drive rods 31 rotate synchronously and can also brake the four walking wheels 4 at the same time.

[0043] Figure 4 yes Figure 2 Schematic diagram of the structure of the locking component 5.

[0044] Reference Figure 3 and Figure 4 In order to further facilitate single-person operation of the movable device, two sets of locking assemblies 5 for locking the rotation direction of the travel wheel 4 are provided on the frame 1. Each set of locking assemblies 5 includes a locking cam 51 and two positioning pins 52 arranged on both sides of the locking cam 51. The locking cam 51 includes a locking base 511 and two locking protrusions 512 fixedly arranged on the outer edge of the locking base 511. The two locking protrusions 512 are arranged opposite to each other, and the locking protrusions 512 and the locking base 511 are integrally formed. A two-way straight-moving linkage rod 53 is provided between the two sets of locking assemblies 5. The two-way straight-moving linkage rod 53 is connected to the frame 1 by rotating around its own axis. A straight-moving locking pedal 531 is provided at each end of the two-way straight-moving linkage rod 53. The locking cams 51 in the two sets of locking assemblies 5 are clamped to the outer peripheral surface of the two-way straight-moving linkage rod 53, and the two locking cams 51 are respectively arranged near the two ends of the two-way straight-moving linkage rod 53. Since the two locking protrusions 512 are relatively arranged on the outer edge of the brake base 211, the line connecting the center positions of the two locking protrusions 512 passes through the center of the brake base 211, and the projections of the locking protrusions 512 of the two locking cams 51 along the axial direction of the two-way straight-moving linkage rod 53 do not overlap, and in the projection figure, the line connecting the two locking protrusions 512 intersects vertically.

[0045] A control box 11 is provided on the outside of the bidirectional straight-moving linkage rod 53. The cross-section of the control box 11 is rectangular and annular. The control box 11 is fixedly mounted on the frame 1 and serves to protect the bidirectional straight-moving linkage rod 53. An L-shaped support base 12 is provided on each side of the control box 11. The support base 12 includes a horizontally arranged transverse plate 121 and a vertical plate 122 detachably connected to the transverse plate 121. One side of the transverse plate 121 is fixedly connected to the outer wall of the control box 11, and the vertical plate 122 is bolted to the side of the transverse plate 121 away from the control box 11. The positioning pin 52 includes a first pin shaft 521 and a second pin shaft 522. The first pin shaft 521 is arranged horizontally and its length direction is radially along the locking base 511. The first end of the first pin shaft 521 passes through the vertical plate 122 and the control box 11 and abuts against the outer circumferential surface of the locking cam 51. A fixing seat 54 is sleeved on the outer circumference of the first pin 521. The fixing seat 54 is located near the second end of the first pin 521. A retaining spring 541 is provided on both sides of the fixing seat 54. The retaining spring 541 engages with the outer circumference of the first pin 521, thereby limiting the relative sliding of the first pin 521 along the axial direction with the fixing seat 54. The second pin 522 is arranged parallel to the first pin 521 and is located below the first pin 521. The second pin 522 is slidably connected to the fixing seat 54.

[0046] Figure 5 yes Figure 4 Schematic diagram of the structure of the locking cam 51.

[0047] Reference Figure 4 and Figure 5 The first pin 521 has a tapered bald end for contacting the locking cam 51. The outer circumference of the locking cam 51 is defined by two first limiting grooves 513, two second limiting grooves 514, and two third limiting grooves 515. The two first limiting grooves 513 are located on the two locking protrusions 512, respectively, and are disposed opposite each other. The two second limiting grooves 514 are located on the locking base 511, and are disposed opposite each other. The line connecting the two second limiting grooves 514 of one locking cam 51 is skewed and perpendicular to the line connecting the two second limiting grooves 514 of the other locking cam 51. The two third limiting grooves 515 are also located on the locking base 511, and are disposed opposite each other. The line connecting the two third limiting grooves 515 is perpendicular to the line connecting the two first limiting grooves 513. Therefore, when the two-way straight-moving linkage rod 53 is rotated, when the first pin shaft 521 of one group of locking components 5 abuts against the first limiting groove 513, the first pin shaft 521 of the other group of locking components 5 abuts against the third limiting groove 515; when the first pin shaft 521 of one group of locking components 5 abuts against the second limiting groove 514, the first pin shaft 521 of the other group of locking components 5 also abuts against the second limiting groove 514.

[0048] Figure 6 yes Figure 2 Schematic diagram of part of the structure of the middle traveling wheel 4.

[0049] Reference Figure 6 The lower end of the frame 1 is fixed with a mounting seat 13 by bolts. The mounting seat 13 is sleeved on the outside of the brake push rod 221. A steering sleeve 14 is fixedly disposed between the mounting seat 13 and the brake push rod 221. The travel wheel 4 includes a roller 41 and a bracket 42 for mounting the roller 41. A radial bearing 15 is embedded in the upper end of the bracket 42. The bracket 42 has an interference fit with the outer ring of the radial bearing 15. The lower end of the steering sleeve 14 is fixedly connected to the inner ring of the radial sleeve, allowing the bracket 42 to rotate 360° around the steering sleeve 14. Considering the weak axial load-bearing capacity of the radial bearing 15, a positioning flange 16 is fixedly mounted on the upper end of the bracket 42 by bolts. A thrust bearing 17 for bearing axial loads is mounted on the inner ring of the positioning flange 16. The thrust bearing 17 sleeves on the outside of the steering sleeve 14. A limiting groove 161 is provided on the outer peripheral surface of the positioning flange 16, and the limiting groove 161 passes through both ends of the positioning flange 16 in the vertical direction. Since the positioning flange 16 rotates synchronously with the bracket 42, when the second pin shaft 522 is inserted into the limiting groove 161, the bracket 42 and the positioning flange 16 cannot rotate around the steering sleeve 14, the direction of the walking wheel 4 is locked, and at this time the axis of the roller 41 is parallel to the second pin shaft 522.

[0050] Reference Figure 4 and Figure 5 At this time, the two first pins 521 on this side are respectively abutted against the two second limiting grooves 514, and the first pin 521 on the other side is also abutted against the second limiting groove 514, that is, the first pins 521 on both sides are abutted against the locking base 511, and the second pins 522 are separated from the positioning flange 16. The rotation direction of the four walking wheels 4 is in an unlocked state and can rotate 360 degrees freely; the operator steps on the straight locking pedal 531 on this side to make the two-way straight linkage rod 53 rotate clockwise, and the first pin 5 21 abuts against the first limiting groove 513, and the second pin shaft 522 is inserted into the limiting groove 161 of the positioning flange 16, so that the directions of the two running wheels 4 on this side are locked in a straight-moving state, and the running wheels 4 on the other side are still in a free-steering state; of course, the operator can also step on the straight-moving locking pedal 531 to make the two-way straight-moving linkage rod 53 rotate counterclockwise, and the first pin shaft 521 abuts against the third limiting groove 515, so that the running wheels 4 on this side remain in a free-steering state, and the running wheels 4 on the other side become straight-moving state.

[0051] The outer circumference of the first pin 521 is provided with a first abutting portion 523, which is located between the riser 122 and the control box 11. A first elastic member 524 is provided between the first abutting portion 523 and the riser 122. The side of the riser 122 closest to the control box 11 serves as the abutting surface 124. The first elastic member 524 is a common coil spring, which is sleeved around the outer circumference of the first pin 521. When free, the length of the first elastic member 524 is greater than the distance between the abutting surface 124 and the control box 11. This means that after installation, the first elastic member 524 is compressed. Under the elastic force of the first elastic member 524, the first pin 521 is constantly in abutment with the outer circumference of the locking cam 51. The outer circumference of the second pin 522 is provided with a second abutting portion 525, which is located on the side of the fixing seat 54 away from the locking cam 51. A second elastic member 526 is provided between the second abutting portion 525 and the fixing seat 54. Similarly, the second elastic member 526 is a coil spring sleeved outside the second pin 522. After installation, the second elastic member 526 is also in a compressed state, so that the second pin 522 abuts against the outer peripheral surface of the positioning flange 16 under the elastic force of the second elastic member 526. The first abutting portion 523 and the second abutting portion 525 are used to limit the first elastic member 524 and the second elastic member 526, respectively. They have the same structure and can be, specifically, a retaining spring or a cotter pin, which is not specifically limited in this embodiment of the present invention.

[0052] The outer circumference of the mounting shaft seat 13 is radially defined with four groups of threaded holes 131 extending through the inner and outer walls of the mounting shaft seat 13. Two groups of threaded holes 131 within the same group are vertically spaced apart, with the axes of adjacent groups of threaded holes 131 forming a 90° angle. A sliding shaft seat 18 is provided on the side of the mounting shaft seat 13 near the locking cam 51. Two fastening bolts 181 are threaded through the sliding shaft seat 18. The two fastening bolts 181 are threadedly engaged with any of the groups of threaded holes 131 on the mounting shaft seat 13, thereby securing the sliding shaft seat 18 to the mounting shaft seat 13. The purpose of providing four groups of threaded holes 131 is to reduce assembly accuracy, thereby preventing the fastening bolts 181 from being unable to engage with the threaded holes 131 due to incorrect installation orientation of the mounting shaft seat 13. A sliding channel 182 is provided on the sliding shaft seat 18, extending horizontally through the sliding shaft seat 18. The diameter of the sliding channel 182 is consistent with the diameter of the second pin 522, and the two are slidably engaged. When the first pin shaft 521 abuts against the locking base 511 of the locking cam 51, the second pin shaft 522 is located in the sliding channel 182 close to the end of the positioning flange 16; when the locking cam 51 rotates, the first pin shaft 521 gradually moves to the locking protrusion 512, and the first pin shaft 521 and the fixing seat 54 gradually move away from the locking cam 51. If the limiting groove 161 of the positioning flange 16 is not aligned with the second pin shaft 522, the second pin shaft 522 abuts against the outer peripheral surface of the positioning flange 16, and the second elastic member 526 is gradually compressed. By rotating the walking wheel 4 to align the limiting groove 161 with the second pin shaft 522, the second pin shaft 522 is inserted into the limiting groove 161 under the push of the second limiting member.

[0053] In conjunction with the above-mentioned drawings, for ease of understanding, a more specific implementation scenario is provided below. In an embodiment of the present invention, the movable device is a medical transport vehicle for transporting patients, and a running wheel 4 is installed at each of the four corners of the lower end of the medical transport vehicle. When a single person moves the medical transport bed, usually the two running wheels 4 on one side are locked in a straight-moving direction, and the directions of the two running wheels 4 on the other side are not locked, which makes it convenient for a single person to push or pull the medical transport bed. In a normal state, the directions of the four running wheels 4 are all unlocked, that is, the first pins 521 of the two sets of locking assemblies 5 abut against the second limiting groove 514 of the locking cam 51. When the first and second locking cams 521 are engaged, the first and second locking cams 522 are engaged with the first and second locking cams 523, 531 and 532, respectively, and the first and second locking cams 521 are engaged with the first and second locking cams 523, 531 and 532, respectively. The operator can control whether the bidirectional straight-moving linkage rod 53 rotates clockwise or counterclockwise by stepping on the direction of the straight-moving locking pedal 531, so that the direction of the two running wheels 4 close to the operator can be locked, or the direction of the two running wheels 4 away from the operator can be locked, depending on actual needs and the operator's habits.

[0054] When the operator needs to fix the medical transfer bed, the operator steps on the brake pedal 311, thereby driving one of the driving rods 31 to rotate. Due to the linkage effect of the brake linkage rod 32 and the connecting swing arm 33, the other driving rod 31 rotates synchronously; the driving rod 31 rotates at the same time with the brake cam 21, and the brake cam 21 pushes the brake push rod 221 to move downward. The friction block 222 at the lower end of the brake push rod 221 abuts against the outer peripheral surface of the roller 41, thereby gradually restricting the roller 41 and braking the four walking wheels 4 at the same time.

[0055] Example 2:

[0056] The difference between the embodiment of the present invention and the embodiment 1 lies in the different arrangement of the driving rod 31, as follows:

[0057] In the embodiment of the present invention, there are a total of four groups of brake assemblies 2 and two drive rods 31. The four groups of brake assemblies 2 correspond one to one to the four running wheels 4. The drive rods 31 are located between the two groups of brake assemblies 2 arranged diagonally, that is, the two drive rods 31 are staggered. The drive rods 31 rotate around their own axes and are connected to the frame 1. A brake pedal 311 is provided at one end of the drive rods 31. The brake cams 21 of the two groups of brake assemblies 2 arranged diagonally are clamped to the outer circumference of the drive rods 31. The two brake cams 21 are arranged near the two ends of the drive rods 31, and the projections of the two brake cams 21 along the axial direction of the drive rods 31 coincide, that is, the two diagonally arranged running wheels 4 can be braked at the same time by rotating the drive rods 31.

[0058] In the description of this specification, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and integrate different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless otherwise inconsistent.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0060] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A linkage locking device, characterized in that: The invention comprises a frame (1) and at least two groups of brake assemblies (2) for braking a traveling wheel (4), wherein the brake assemblies (2) comprise a brake cam (21) and a brake member (22) slidingly arranged relative to the traveling wheel (4), a driving rod (31) is provided between the two groups of the brake assemblies (2), and the driving rod (31) is connected in series with the two brake cams (21) to form a two-wheel brake module; under the rotation of the driving rod (31), the brake cams (21) in the two brake assemblies (2) rotate simultaneously to drive the two brake members (22) to lock or disengage the two traveling wheels (4) respectively; When the travel wheel (4) is a universal wheel, a locking assembly (5) is provided on the frame (1), and the locking assembly (5) includes a rotatably arranged locking cam (51) and two positioning pins (52) relatively arranged on both sides of the locking cam (51); a positioning flange (16) for fixedly connecting the travel wheel (4) is rotatably provided on the frame (1); under the rotation of the locking cam (51), the positioning pins (52) are used to lock or disengage from the positioning flange (16) to achieve locking or unlocking of the rotation direction of the travel wheel (4); The locking assembly (5) is provided with two groups and is arranged opposite to each other. A bidirectional straight-moving linkage rod (53) is rotatably connected to the frame (1). The bidirectional straight-moving linkage rod (53) is connected in series with the two locking cams (51). The projections of the two locking cams (51) along the axial direction of the bidirectional straight-moving linkage rod (53) do not overlap.

2. The linkage locking device according to claim 1, characterized in that: The brake components (2) are provided in four groups, and the driving rods (31) are provided in two groups and are arranged in parallel.

3. The linkage locking device according to claim 2, characterized in that: A linkage assembly (3) is provided between the two driving rods (31). Under the transmission of the linkage assembly (3), the two driving rods (31) rotate synchronously. The driving rods (31) and the linkage assembly (3) constitute a four-wheel brake module.

4. The linkage locking device according to claim 1, characterized in that: The brake assemblies (2) are provided with four groups, the drive rods (31) are provided with two groups, and the drive rods (31) are located between two brake assemblies (2) that are arranged diagonally.

5. The linkage locking device according to claim 1, characterized in that: The locking cam (51) comprises a locking base (511) and two locking protrusions (512) arranged opposite to the locking base (511), each of the two locking protrusions (512) being provided with a first limiting groove (513) for accommodating the end of the positioning pin (52), and the two first limiting grooves (513) are arranged opposite to each other.

6. The linkage locking device according to claim 5, characterized in that: The locking base (511) is provided with two second limiting grooves (514) for accommodating the ends of the positioning pin (52), the two second limiting grooves (514) being arranged opposite to each other, and the second limiting grooves (514) of the two locking cams (51) are overlapped in their axial projection along the bidirectional straight-moving linkage rod (53).

7. The linkage locking device according to claim 1, characterized in that: The outer peripheral surface of the positioning pin (52) is provided with a first abutting portion (523); the frame (1) includes an abutting surface (124) located on the side of the first abutting portion (523) away from the locking cam (51); the positioning pin (52) passes through the abutting surface (124); a first elastic member (524) is provided between the abutting surface (124) and the first abutting portion (523); the first elastic member (524) is used to push the positioning pin (52) to abut against the locking cam (51).

8. The linkage locking device according to claim 1, characterized in that: The positioning pin (52) includes a first pin shaft (521) for abutting the outer peripheral surface of the locking cam (51) and a second pin shaft (522) for abutting the positioning flange (16), the first pin shaft (521) is fixedly connected to a fixing seat (54), the second pin shaft (522) is axially slidably connected to the fixing seat (54), the outer peripheral surface of the second pin shaft (522) is provided with a second abutting portion (525), a second elastic member (526) is provided between the second abutting portion (525) and the fixing seat (54), and the second elastic member (526) is used to push the second pin shaft (522) to lock the positioning flange (16).

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