1. The linkage locking device is characterized by comprising a rack (1) and at least two groups of braking components (2) for braking a travelling wheel (4), wherein each braking component (2) comprises a braking cam (21) and a braking piece (22) which is arranged in a sliding mode relative to the travelling wheel (4), a driving rod (31) is arranged between the two groups of braking components (2), and the driving rods (31) are connected with the two braking cams (21) in series to form a two-wheel braking module; under the rotation of the driving rod (31), the two brake cams (21) in the brake component (2) rotate simultaneously to drive the two brake pieces (22) to be locked or separated from the two travelling wheels (4) respectively.

2. A linked locking device according to claim 1, characterised in that said braking assembly (2) is provided in four groups, and said driving rods (31) are provided in two and parallel arrangements.

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

4. The device according to claim 1, characterized in that said braking assemblies (2) are provided in four groups, said driving rod (31) is provided in two groups, and said driving rod (31) is located between two braking assemblies (2) arranged diagonally.

5. The linkage locking device according to claim 1, characterized in that when the travelling wheel (4) is a universal wheel, a locking assembly (5) is arranged on the frame (1), the locking assembly (5) comprises a locking cam (51) which is rotatably arranged and two positioning pins (52) which are oppositely arranged on two sides of the locking cam (51), a positioning flange (16) which is fixedly connected with the travelling wheel (4) is rotatably arranged on the frame (1), and under the rotation of the locking cam (51), the positioning pins (52) are used for locking or disengaging the positioning flange (16) so as to lock or unlock the rotation direction of the travelling wheel (4).

6. The linkage locking device according to claim 5, characterized in that the locking assemblies (5) are provided with two groups and arranged oppositely, a bidirectional rectilinear linkage rod (53) is rotatably connected to the frame (1), the bidirectional rectilinear linkage rod (53) is connected in series with the two locking cams (51), and the two locking cams (51) do not overlap in axial projection along the bidirectional rectilinear linkage rod (53).

7. The interlocking lock device according to claim 6, characterized in that the locking protrusion (512) comprises a locking base (511) and two locking protrusions (512) oppositely arranged on the locking base (511), each of the two locking protrusions (512) is provided with a first limiting groove (513) for accommodating the end of the positioning pin (52), and the two first limiting grooves (513) are oppositely arranged.

8. The linkage locking device according to claim 7, characterized in that two second limiting grooves (514) for accommodating the ends of the positioning pins (52) are arranged on the locking base (511), the two second limiting grooves (514) are arranged oppositely, and the second limiting grooves (514) of the two locking cams (51) are overlapped along the axial projection of the two-way rectilinear linkage rod (53).

9. The linkage locking device according to claim 5, wherein a first abutting portion (523) is provided on an outer peripheral surface of the positioning pin (52), the frame (1) includes an abutting surface (124) located on a side of the first abutting portion (523) away from the locking cam (51), the positioning pin (52) penetrates through the abutting surface (124), a first elastic member (524) is provided between the abutting surface (124) and the first abutting portion (523), and the first elastic member (524) is used for pushing the positioning pin (52) to abut against the locking cam (51).

10. The linkage locking device according to claim 5, wherein the positioning pin (52) comprises a first pin (521) for abutting against the outer peripheral surface of the locking cam (51) and a second pin (522) for abutting against the positioning flange (16), the first pin (521) is fixedly connected with a fixed seat (54), the second pin (522) is axially slidably connected to the fixed seat (54), a second abutting portion (525) is arranged on the outer peripheral surface of the second pin (522), a second elastic member (526) is arranged between the second abutting portion (525) and the fixed seat (54), and the second elastic member (526) is used for pushing the second pin (522) to lock the positioning flange (16).

Background

Generally, four walking wheels which are arranged in a rectangular shape are installed at the lower end of a movable device such as a cart and a movable bed, so that an operator can move the movable device conveniently, and the walking wheels can be straight wheels or universal wheels.

In the prior art, each walking wheel is correspondingly provided with a brake structure, and at least any two walking wheels need to be braked, so that the movable device can be fixed and limited. Therefore, during the braking process of the movable device, the operator needs to perform at least two braking actions, which is inconvenient to operate to a certain extent.

Disclosure of Invention

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

In order to solve the technical problems and achieve the purpose, the invention provides a linkage locking device which comprises a rack and at least two groups of braking components for braking walking wheels, wherein each braking component comprises a braking cam and a braking piece which is arranged in a sliding manner relative to the walking wheels, a driving rod is arranged between the two groups of braking components, and the driving rod is connected with the two braking cams in series to form a two-wheel braking module; under the rotation of the driving rod, the brake cams in the two brake assemblies rotate simultaneously to drive the two brake pieces to respectively lock or separate from the two travelling wheels.

In one embodiment, the brake assembly is provided in four sets, and the driving rods are provided in two sets and arranged in parallel.

In an implementation mode, a linkage assembly is arranged between the two driving moving rods, the two driving rods synchronously rotate under the transmission of the linkage assembly, and the driving rods and the linkage assembly form a four-wheel brake module.

In one embodiment, there are four sets of the braking assemblies, there are two driving rods, and the driving rods are located between two braking assemblies which are diagonally arranged.

In an implementation mode, when the walking wheel is the universal wheel, be provided with the locking subassembly in the frame, the locking subassembly including rotate the locking cam that sets up and two relative set up in the locating pin of locking cam both sides, it is provided with to rotate in the frame and is used for fixed connection the locating flange of walking wheel under the rotation of locking cam, the locating pin is used for the locking or breaks away from locating flange to the realization is right the locking or the unblock of walking wheel rotation direction.

In an implementation manner, two groups of locking assemblies are arranged oppositely, a bidirectional straight-going linkage rod is rotatably connected to the rack, the bidirectional straight-going linkage rod is connected with two locking cams in series, and the two locking cams do not coincide with each other along the axial projection of the bidirectional straight-going linkage rod.

In an embodiment, the locking protrusion includes a locking base and two locking protrusions oppositely disposed on the locking base, each of the two locking protrusions has a first limiting groove for accommodating an end of the positioning pin, and the two first limiting grooves are oppositely disposed.

In an implementation manner, two second limiting grooves for accommodating end portions of the positioning pins are formed in the locking base portion, the two second limiting grooves are arranged oppositely, and projections of the second limiting grooves of the two locking cams along the axial direction of the bidirectional straight linkage rod are overlapped.

In an implementation manner, the outer circumferential surface of the positioning pin is provided with a first abutting portion, the frame includes an abutting surface located on a side of the first abutting portion away from the locking cam, the positioning pin penetrates through the abutting surface, and a first elastic member is arranged between the abutting surface and the first abutting portion and used for pushing the positioning pin to abut against the locking cam.

In an implementation mode, the positioning pin comprises a first pin shaft used for being abutted to the peripheral surface of the locking cam and a second pin shaft used for being abutted to the positioning flange, the first pin shaft is fixedly connected with a fixed seat, the second pin shaft is connected to the fixed seat in a sliding mode along the axial direction, a second abutting portion is arranged on the peripheral surface of the second pin shaft, a second elastic part is arranged between the second abutting portion and the fixed seat, and the second elastic part is used for pushing the second pin shaft to be abutted to the positioning flange. Compared with the prior art, the linkage locking device has the following beneficial effects:

1. by arranging the driving rod, the driving rod is connected with the brake cams of any two groups of brake assemblies, so that the driving rod can be rotated to simultaneously drive the two brake cams to rotate, and further the two travelling wheels are braked, an operator can limit and fix the movable device only by performing a braking action once, the operation steps in the braking process are reduced, and the operation convenience is improved;

2. by arranging four groups of brake assemblies and two driving rods arranged in parallel, the brake assemblies are linked pairwise, and an operator can fix the movable device by rotating any one driving rod, so that the operation convenience is further improved;

3. by arranging the linkage assembly, an operator rotates one of the driving rods, and the other driving rod synchronously rotates, so that the four travelling wheels are simultaneously braked, and compared with the braking mode of two travelling wheels, the braking mode of the two travelling wheels is beneficial to increasing the resistance for pushing or pulling the movable device, and the limiting stability of the movable device is improved;

4. because the driving rods are arranged between the two groups of brake assemblies which are arranged diagonally, the two driving rods are in an intersecting state and have the same effect as the scheme that the two driving rods are arranged in parallel, and an operator can complete the fixation of the movable device by rotating any one driving rod;

5. the locking assembly is arranged, and the locking cam is rotated, so that the two positioning pins can be locked or separated from the positioning flange, and the rotation direction of the travelling wheel is locked or unlocked; because the directions of the four travelling wheels are not locked, a single person is difficult to push or pull the movable device at a certain side, and an operator can lock the directions of the two travelling wheels at a certain side through the structure, so that the operator can push or pull the movable device conveniently;

6. by arranging the bidirectional straight-going linkage rod and enabling the two locking cams to be not overlapped along the axial projection, when the positioning pin of one locking assembly locks the positioning flange on one side, the positioning pin of the other locking assembly is separated from the positioning flange on the corresponding side, namely the two walking wheels on one side are locked, and the two walking wheels on the other side are unlocked, so that the convenience of single operation is improved under the condition that the movable device can be steered;

7. by arranging the first limiting groove, the first end of the positioning pin is prevented from sliding out of the locking convex part as much as possible, and the traveling wheel on the side is favorably maintained in a direction locking state;

8. by arranging 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 grooves, and the directions of the four travelling wheels on the two sides are in an unlocked state, so that the movement flexibility of the movable device is improved to meet the actual operation requirement;

9. the first elastic piece is arranged, so that the positioning pin is tightly abutted to the locking cam under the action of the elastic force of the first elastic piece, and the positioning pin and the locking cam are kept in a contact state, so that the rotation direction of the travelling wheel can be locked by the locking cam;

10. by arranging the fixed seat, the second elastic part and the second pin shaft, when the first pin shaft abuts against the locking convex part, the second pin shaft has a movement trend of locking the positioning flange under the pushing of the second elastic part, so that the locking action of the positioning flange is realized;

therefore, the invention has the characteristics of convenient operation, good flexibility and the like.

Drawings

FIG. 1 is a top view of the present invention;

FIG. 2 is a cross-sectional view of the present invention;

FIG. 3 is a schematic diagram of a break in the present invention;

FIG. 4 is a schematic view of the structure at the locking assembly of FIG. 2;

FIG. 5 is a schematic view of the locking cam of FIG. 4;

fig. 6 is a partial structural view of the traveling wheel of fig. 2.

The reference numbers in the figures illustrate: 1. a frame; 11. a control box; 12. a supporting seat; 121. a transverse plate; 122. a vertical plate; 124. an abutting surface; 13. installing a shaft seat; 131. a threaded hole; 14. a steering shaft sleeve; 15. a radial bearing; 16. positioning the flange; 161. a limiting groove; 17. a thrust bearing; 18. a sliding shaft seat; 181. fastening a bolt; 182. a slipping channel; 2. a brake assembly; 21. a brake cam; 211. a brake base; 212. a brake projection; 22. a braking member; 221. a brake push rod; 222. a friction block; 3. a linkage assembly; 31. a drive rod; 311. a brake pedal; 32. a brake linkage rod; 33. connecting the swing arm; 4. a traveling wheel; 41. a roller; 42. a support; 5. a locking assembly; 51. a locking cam; 511. a locking base; 512. a locking projection; 513. a first limit groove; 514. a second limit groove; 515. a third limiting groove; 52. positioning pins; 521. a first pin shaft; 522. a second pin shaft; 523. a first abutting portion; 524. a first elastic member; 525. a second abutting portion; 526. a second elastic member; 53. a bidirectional straight-going linkage rod; 531. a straight-moving locking pedal; 54. a fixed seat; 541. and a clamp spring.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

FIG. 1 is a top view of the present invention; fig. 2 is a cross-sectional view of the present invention.

Referring to fig. 1 and 2, a linkage locking device includes a frame 1 and at least two sets of brake assemblies 2 for braking road wheels 4, each set of brake assemblies 2 including a brake cam 21 and a brake piece 22. Under the rotation of the brake cam 21, the brake piece 22 is used for locking or disengaging the travelling wheels 4, so that whether the travelling wheels 4 are braked or not is realized. And a driving rod 31 is arranged between the two groups of braking assemblies 2, and the driving rod 31 is connected with the braking cams 21 in the two groups of braking assemblies 2 in series, so that a two-wheel braking module is formed. The embodiment of the invention aims to enable the two brake cams 21 to synchronously rotate by arranging the driving rod 31, so that the two brake pieces 22 respectively brake the two travelling wheels 4, an operator can limit and fix the movable device by only one braking action, the operation steps in the braking process are reduced, and the operation convenience is improved.

The embodiment of the invention mainly aims at a movable device provided with four walking wheels 4, wherein the four walking wheels 4 are arranged at the lower end of a rack 1, the rack 1 is arranged at the lower end of the movable device, and the four walking wheels 4 are usually in a rectangular array. The movable device can be a trolley, a medical transfer bed and the like, the walking wheels 4 can be straight wheels or universal wheels, and in the embodiment of the invention, the walking wheels 4 are universal wheels.

In the embodiment of the invention, four groups of brake assemblies 2 and two driving rods 31 are provided, the four groups of brake assemblies 2 correspond to the four travelling wheels 4 one by one, and the driving rods 31 are arranged between two adjacent groups of brake assemblies 2, namely, the two driving rods 31 are arranged in parallel. The driving rod 31 is rotatably connected to the frame 1 around its own axis, and one end of the driving rod 31 is provided with a brake pedal 311. The brake cam 21 includes a cylindrical brake base 211 and a brake protrusion 212 fixedly disposed on an outer wall of the brake base 211, and the brake base 211 and the brake protrusion 212 are integrally formed. The brake cams 21 in two sets of adjacent braking components 2 are clamped on the peripheral surface of the driving rod 31, two brake cams 21 are arranged near the two ends of the driving rod 31, and the axial projections of the two brake cams 21 along the driving rod 31 are overlapped, namely, the driving rod 31 can be rotated to simultaneously brake the two traveling wheels 4 on one side.

After the clamping is completed, the brake cam 21 and the driving rod 31 do not have a degree of freedom of relative movement, so the clamping manner may be welding, bolt fixing, and the like, and the embodiment of the present invention is not limited to this. The brake member 22 includes a brake push rod 221 slidably connected to the frame 1 in a vertical direction and a friction block 222 installed at a lower end of the brake push rod 221, and a coil spring (not shown) is provided at the brake push rod 221 so that the brake push rod 221 abuts against an outer circumferential surface of the brake cam 21 by an elastic force. The friction block 222 needs to be formed by processing a material with a relatively large friction coefficient, which may be an asbestos-based friction material, a semi-metal-based friction material, or a non-asbestos mixed fiber-based friction material, and the embodiment of the present invention is not limited thereto. It will be appreciated that the direction of sliding connection of the brake member 22 to the frame 1 may be vertical, but other directions are also possible.

When braking, an operator steps on the brake pedal 311, the driving rod 31 and the two brake cams 21 rotate synchronously, the upper end of the brake push rod 221 moves from the brake base 211 of the brake cam 21 to the brake convex part 212, so that the brake push rod 221 slides downwards, the friction block 222 at the lower end of the brake push rod 221 abuts against the outer peripheral surface of the traveling wheel 4, the traveling wheel 4 is subjected to the dynamic friction force applied by the friction block 222 and stops rotating gradually, and the braking process of the two traveling wheels 4 on the same side is completed.

Fig. 3 is a schematic diagram of a break in the present invention.

Referring to fig. 1 and 3, a linkage assembly 3 is arranged between the two driving rods 31, the linkage assembly 3 includes a brake linkage rod 32 and two connecting swing arms 33 respectively hinged at two ends of the brake linkage rod 32, and the brake linkage rod 32 and the driving rods 31 form a four-wheel brake module. One end of the connecting swing arm 33, which is far away from the brake linkage rod 32, is sleeved on the peripheral surface of the driving rod 31, the connecting swing arm 33 and the driving rod 31 are clamped, and the connecting swing arm 33 and the driving rod 31 do not have relative rotation freedom, so that the invention does not limit the specific clamping mode. One of the driving rods 31 is rotated, and the other driving rod 31 rotates 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, an operator steps on any one brake pedal 311, so that the two driving rods 31 synchronously rotate, and the four travelling wheels 4 are braked simultaneously. It is easy to understand that the linkage assembly 3 can also be in other transmission structures, for example, the ends of the driving rod 31 and the brake linkage rod 32 are connected in a bevel gear engagement manner, so that the two driving rods 31 rotate synchronously, and the four road wheels 4 can be braked simultaneously.

Fig. 4 is a schematic view of the structure of fig. 2 at the locking assembly 5.

Referring to fig. 3 and 4, to further facilitate the operation of the mobile device by a single person, the frame 1 is provided with two sets of locking assemblies 5 for locking the rotation directions of the road wheels 4. Each set of locking components 5 comprises a locking cam 51 and two positioning pins 52 arranged on two sides of the locking cam 51, the locking cam 51 comprises 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 oppositely, and the locking protrusions 512 and the locking base 511 are integrally formed. A bidirectional straight-going linkage rod 53 is arranged between the two groups of locking components 5, the bidirectional straight-going linkage rod 53 is rotatably connected to the rack 1 around the axis thereof, and two straight-going locking pedals 531 are respectively arranged at two ends of the bidirectional straight-going linkage rod 53. The locking cams 51 in the two groups of locking assemblies 5 are clamped on the peripheral surface of the bidirectional straight linkage rod 53, and the two locking cams 51 are respectively arranged close to the two ends of the bidirectional straight linkage rod 53. Because the two locking protrusions 512 are oppositely arranged at the outer edge of the brake base 211, the connecting line of the center positions of the two locking protrusions 512 passes through the center of the brake base 211, the axial projections of the locking protrusions 512 of the two locking cams 51 along the bidirectional rectilinear linkage rod 53 are not overlapped, and in the projection graph, the connecting line of the two locking protrusions 512 is vertically crossed.

The outer side of the bidirectional straight-going linkage rod 53 is provided with a control box 11, the section of the control box 11 is in a rectangular ring shape, and the control box 11 is fixedly installed on the rack 1 and used for protecting the bidirectional straight-going linkage rod 53. The two sides of the control box 11 are respectively provided with an L-shaped supporting seat 12, the supporting seat 12 comprises a horizontal plate 121 horizontally arranged and a vertical plate 122 detachably connected to the horizontal plate 121, one side of the horizontal plate 121 is fixedly connected to the outer wall of the control box 11, and the vertical plate 122 is connected to one side of the horizontal plate 121 far away from the control box 11 through bolts. The positioning pin 52 includes a first pin 521 and a second pin 522, the first pin 521 is horizontally disposed and has a length direction along a radial direction of the locking base 511, and a first end of the first pin 521 penetrates the riser 122 and the control box 11 and abuts against an outer peripheral surface of the locking cam 51. The fixing seat 54 is sleeved on the outer peripheral surface of the first pin 521, the fixing seat 54 is close to the second end of the first pin 521, clamp springs 541 are arranged on two sides of the fixing seat 54, and the clamp springs 541 are clamped on the outer peripheral surface of the first pin 521, so that the first pin 521 is limited to slide relative to the fixing seat 54 along the axial direction. The second pin 522 is disposed parallel to the first pin 521 and located below the first pin 521, and the second pin 522 is slidably connected to the fixing base 54.

Fig. 5 is a schematic structural view of the locking cam 51 in fig. 4.

Referring to fig. 4 and 5, one end of the first pin 521, which is used to abut against the locking cam 51, is a tapered end, and the outer circumferential surface of the locking cam 51 is provided with two first limiting grooves 513, two second limiting grooves 514, and two third limiting grooves 515. The two first limiting grooves 513 are respectively located on the two locking protrusions 512 and are oppositely arranged; the two second limiting grooves 514 are positioned on the locking base 511 and are oppositely arranged, and the connecting line of the two second limiting grooves 514 of one locking cam 51 is perpendicular to the connecting line of the two second limiting grooves 514 of the other locking cam 51; two third limiting grooves 515 are also located at the locking base 511 and are oppositely arranged, and the line of the two third limiting grooves 515 is perpendicular to the line of the two first limiting grooves 513. Therefore, when the two-way linkage rod 53 is rotated, the first pin 521 of one of the locking elements 5 abuts against the first limiting groove 513, and the first pin 521 of the other locking element 5 abuts against the third limiting groove 515; when the first pin 521 of one of the locking elements 5 abuts against the second limiting recess 514, the first pin 521 of the other locking element 5 also abuts against the second limiting recess 514.

Fig. 6 is a partial structural view at the travel wheel 4 in fig. 2.

Referring to fig. 6, a mounting shaft seat 13 is fixed to the lower end of the frame 1 through a bolt, the mounting shaft seat 13 is sleeved on the outer side of the brake push rod 221, a steering shaft sleeve 14 is further arranged between the mounting shaft seat 13 and the brake push rod 221, and the steering shaft sleeve 14 is fixedly arranged. The road wheel 4 comprises a roller 41 and a bracket 42 for mounting the roller 41, a radial bearing 15 is embedded at the upper end of the bracket 42, the bracket 42 is in interference fit with the outer ring of the radial bearing 15, and the lower end of the steering shaft sleeve 14 is fixedly connected with the inner ring of the radial shaft sleeve, so that the bracket 42 can rotate 360 degrees around the steering shaft sleeve 14. Considering that the radial bearing 15 has a weak bearing capacity in the axial direction, a positioning flange 16 is fixedly arranged at the upper end of the bracket 42 through bolts, a thrust bearing 17 for bearing an axial load is mounted on an inner ring of the positioning flange 16, and the thrust bearing 17 is sleeved outside the steering sleeve 14. The outer peripheral surface of the positioning flange 16 is provided with a limiting groove 161, the limiting groove 161 penetrates through two ends of the positioning flange 16 along the vertical direction, because the positioning flange 16 and the bracket 42 rotate synchronously, when the second pin roll 522 is inserted into the limiting groove 161, the bracket 42 and the positioning flange 16 cannot rotate around the steering shaft sleeve 14, the direction of the walking wheel 4 is locked, and the axis of the roller 41 is parallel to the second pin roll 522 at the moment.

Referring to fig. 4 and 5, at this time, the two first pin shafts 521 on the side abut against the two second limiting grooves 514 respectively, and the first pin shafts 521 on the other side also abut against the second limiting grooves 514, that is, the first pin shafts 521 on the two sides abut against the locking base 511, the second pin shafts 522 are separated from the positioning flange 16, and the four road wheels 4 are in an unlocked state in the rotation direction and can freely rotate for 360 degrees; an operator steps on the straight-running locking pedal 531 at the side by feet to enable the bidirectional straight-running linkage rod 53 to rotate clockwise, the first pin roll 521 abuts against the first limiting groove 513, and the second pin roll 522 is inserted into the limiting groove 161 of the positioning flange 16, so that the directions of the two walking wheels 4 at the side are locked in a straight-running state, and the walking wheels 4 at the other side are still in a free steering state; of course, the operator can also step on the straight locking pedal 531 by foot to make the bidirectional straight linkage rod 53 rotate counterclockwise, the first pin 521 abuts against the third limiting groove 515, so that the road wheel 4 on the side keeps a free steering state, and the road wheel 4 on the other side becomes a straight state.

The first pin 521 is provided with a first contact portion 523 on an outer peripheral surface thereof, the first contact portion 523 is located between the vertical plate 122 and the control box 11, a first elastic member 524 is provided between the first contact portion 523 and the vertical plate 122, and a contact surface 124 is formed on a side surface of the vertical plate 122 close to the control box 11. The first elastic element 524 is a common spiral spring, the first elastic element 524 is sleeved on the outer circumferential surface of the first pin 521, and the length of the first elastic element 524 in a free state is greater than the distance between the abutting surface 124 and the control box 11, that is, the first elastic element 524 is in a compressed state after being installed, and the first pin 521 is always abutted against the outer circumferential surface of the locking cam 51 under the elastic force of the first elastic element 524. The outer peripheral surface of the second pin 522 is provided with a second abutting portion 525, the second abutting portion 525 is located on one side of the fixed seat 54 far away from the locking cam 51, and a second elastic element 526 is arranged between the second abutting portion 525 and the fixed seat 54. Similarly, the second elastic element 526 is a coil spring sleeved on the outer side of the second pin 522, and the second elastic element 526 is also in a compressed state after being installed, 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 element 526. The first abutting portion 523 and the second abutting portion 525 are used for respectively limiting the first elastic member 524 and the second elastic member 526, and have the same structure, specifically, the first abutting portion may be a snap spring, and the second abutting portion may be a cotter pin, which is not specifically limited in this embodiment of the present invention.

The peripheral surface of installation axle bed 13 is seted up four sets of screw holes 131 that run through the installation axle bed 13 inside and outside wall along radial, and two sets of screw holes 131 in the same group are arranged along vertical direction interval, and the axis contained angle that adjacent two sets of screw holes 131 correspond is 90. The side of the installation shaft seat 13 close to the locking cam 51 is provided with a sliding shaft seat 18, two fastening bolts 181 penetrate through the sliding shaft seat 18, and the two fastening bolts 181 are in threaded connection with any group of threaded holes 131 on the installation shaft seat 13, so that the sliding shaft seat 18 is fixed on the installation shaft seat 13. The four sets of threaded holes 131 are provided to reduce the assembly accuracy, thereby avoiding a situation in which the fastening bolt 181 cannot be coupled to the threaded holes 131 due to a wrong mounting direction of the mounting shaft seat 13. The sliding shaft seat 18 is provided with a sliding channel 182 which penetrates through the sliding shaft seat 18 along the horizontal direction, the diameter of the sliding channel 182 is consistent with that of the second pin 522, and the sliding channel 182 and the second pin 522 are in sliding fit. When the first pin 521 abuts against the locking base 511 of the locking cam 51, one end of the second pin 522 close to the positioning flange 16 is located in the sliding channel 182; when the locking cam 51 rotates, in the process that the first pin 521 gradually moves to the locking protrusion 512, the first pin 521 and the fixing base 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 522, the second pin 522 abuts against the outer circumferential surface of the positioning flange 16, the second elastic element 526 is gradually compressed, and the limiting groove 161 is aligned with the second pin 522 by rotating the traveling wheel 4, so that the second pin 522 is inserted into the limiting groove 161 under the pushing of the second limiting element.

In order to facilitate understanding, a more specific implementation scenario is provided below in conjunction with the above-mentioned figures. In the embodiment of the invention, the movable device is a medical transfer trolley for transferring patients, and four corners of the lower end of the medical transfer trolley are respectively provided with a traveling wheel 4. When a single person moves the medical transfer bed, the two walking wheels 4 on one side are locked to be in a straight line, and the two walking wheels 4 on the other side are not locked, so that the single person can push or pull the medical transfer bed conveniently. In the normal state, the directions of the four road wheels 4 are all the unlocked state, i.e. the first pin 521 of the two sets of locking assemblies 5 abuts against the second limit groove 514 of the locking cam 51. In order to realize the effect of single-side locking, an operator steps on the straight-running locking pedal 531 on one side to rotate the bidirectional straight-running linkage rod 53, the locking cam 51 rotates synchronously with the bidirectional straight-running linkage rod 53, the first pin shaft 521 moves from the second limiting groove 514 to the first limiting groove 513, the first pin shaft 521 and the fixed seat 54 are far away from the bidirectional straight-running linkage rod 53 under the pushing of the locking cam 51, the second pin shaft 522 abuts against the outer peripheral surface of the positioning flange 16, and then the travelling wheels 4 are rotated, so that the second pin shaft 522 is inserted into the limiting groove 161, and the two travelling wheels 4 on the side are locked in a straight-running state; at this time, the first pin 521 on the other side abuts against the third limiting groove 515, and the second pin 522 does not abut against the outer peripheral surface of the positioning flange 16, so that the directions of the two travelling wheels 4 on the other side are not locked, which is convenient for a single person to move the medical transfer bed. The operator can be through the two-way rectilinear gangbar 53 of direction control clockwise or anticlockwise rotation of foot-operated rectilinear locking footboard 531 to can be with the direction locking of two walking wheels 4 that are close to the operator, also can be with the direction locking of two walking wheels 4 of keeping away from the operator, according to actual need and operator's custom.

When an operator needs to fix the medical transfer bed, the operator steps on the brake pedal 311 with feet, so as to drive one of the driving rods 31 to rotate, and due to the linkage effect of the brake linkage rod 32 and the connecting swing arm 33, the other driving rod 31 synchronously rotates; the driving lever 31 rotates with the brake cam 21, the brake cam 21 pushes the brake push rod 221 to move downward, and the friction block 222 at the lower end of the brake push rod 221 abuts against the outer circumferential surface of the roller 41, thereby gradually restricting the roller 41 and braking the four road wheels 4.

Example 2:

the embodiment of the present invention is different from embodiment 1 in the arrangement of the driving rod 31, which is as follows:

in the embodiment of the invention, four groups of brake assemblies 2 and two driving rods 31 are arranged, the four groups of brake assemblies 2 correspond to the four travelling wheels 4 one by one, and the driving rods 31 are positioned between the two groups of brake assemblies 2 which are arranged diagonally, namely the two driving rods 31 are arranged in a staggered manner. The driving rod 31 is rotatably connected to the frame 1 around its own axis, and one end of the driving rod 31 is provided with a brake pedal 311. The brake cams 21 of two sets of brake assemblies 2 that are the diagonal and arrange, the joint in the outer peripheral face of actuating lever 31, two brake cams 21 are close to the both ends setting of actuating lever 31 to two brake cams 21 coincide along the axial projection of actuating lever 31, can be through rotating actuating lever 31 simultaneously to being the braking of two walking wheels 4 that the diagonal was arranged promptly.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

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

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.