Electric assist drive device and hospital bed having the same

Abstract

An electric assist drive device and a hospital bed having the same. The electric assist drive device includes a mounting bracket (10) fixedly connected to furniture, a swing lever (20) provided with a rotatable roller (21) at a first end and having a second end hingedly connected to the mounting bracket (10), a traction device (50) connected to the swing lever (20) and drivingly connected to the roller (21), a lifting device (30) including a slider (44) that moves linearly along with a drive device, the drive device driving the rotation of the swing lever (20) by driving the movement of the slider (44), and a balance device (40) including a spring support lever (43), a first end of the spring support lever (43) being hingedly connected to the swing lever (20) and a second end of the spring support lever (43) being hingedly connected to the slider (44). The electric assist drive device can solve the problem that the occupied space of the auxiliary driver in the related art is large.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the priority of a patent application filed with the State Intellectual Property Office of China on June 23, 2022, with the application number 202210719281.0 and the title of the invention being "Electric Assist Driving Device and Hospital Bed Having the Same".

[0002] This application relates to the field of smart home technologies, and specifically, to an electric assist driving device and a hospital bed having the same.

Background Art

[0003] The emergence of movable furniture, especially movable beds, brings convenience to people's daily lives. Usually, four rotatable rollers are provided at the four corners of a movable bed. During the moving process, the rotation of the rollers greatly reduces the frictional force between the bed and the ground, further achieving the purpose of labor saving.

[0004] In related technologies, in order to further relieve the pressure on the operator, an auxiliary driver is also provided on the movable bed. The auxiliary driver includes a roller and a motor drivingly connected to the roller, and the motor can be used to drive the rotation of the roller. Moreover, a spring is provided between the bed and the roller to keep the roller in close contact with the bottom surface at all times. However, the auxiliary driver in related technologies is arranged in the vertical direction and requires a very large space in the height direction.

Summary of the Invention

Problems to be Solved by the Invention

[0005] This application provides an electric assist driving device and a hospital bed having the same to solve the problem that the occupied space of the auxiliary driver in related technologies is large.

Means for Solving the Problems

[0006] According to one aspect of the present application, an electric assist drive device is provided. The electric assist drive device includes a mounting bracket fixedly connected to furniture, a swing lever provided with a rotatable roller at a first end and hinge-connected to the mounting bracket at a second end, a traction device connected to the swing lever and drivingly connected to the roller by the traction device, a lifting device including a slider that moves linearly along with a drive device, the drive device driving the rotation of the swing lever by driving the movement of the slider, and a balance device including a spring support lever, a first end of the spring support lever being hinge-connected to the swing lever and a second end of the spring support lever being hinge-connected to the slider.

[0007] Furthermore, the balance device further includes a guide structure. The guide structure extends linearly and includes a guide element and a guide groove. The guide element is inserted into the guide groove, the guide groove is provided in one of the mounting bracket or the slider, and the guide element is provided in the other of the mounting bracket or the slider.

[0008] Furthermore, the guide element includes a linear guide rail provided on a side wall of the slider, two parallel guide plates are provided on the mounting bracket, and the space between the two guide plates surrounds the guide groove, or the guide element includes a linear guide rail provided on a bottom wall of the slider, two parallel guide ribs are provided on the mounting bracket, and the space between the two guide ribs surrounds the guide groove.

[0009] Furthermore, the drive device includes a first gear motor and a first main shaft. The first gear motor drives the rotation of the first main shaft. The first main shaft has a male thread, a first threaded hole is provided in the slider, and the male thread is screwed into the first threaded hole.

[0010] Furthermore, the drive device includes a drive motor and a second main shaft drivingly connected to the drive motor. The second main shaft is connected to the slider and drives the slider to move linearly.

[0011] Furthermore, the lifting device further includes a turbine and a worm that are relatively rotatable and cooperate with each other. The drive motor includes a second gear motor. The output end of the second gear motor is drivingly connected to the worm. The teeth of the worm mesh with the external teeth of the turbine. The turbine has a second threaded hole. The second main shaft is inserted through the second threaded hole and screwed to the turbine.

[0012] Furthermore, the lifting device further includes a turbine case fixedly connected to the mounting bracket. The turbine is provided within the turbine case. The lifting device further includes a first rolling bearing and a second rolling bearing. The turbine case includes a connected first turbine half shell and a second turbine half shell. The inner rings of the first rolling bearing and the second rolling bearing are respectively fitted at both ends of the turbine. The first turbine half shell and the second turbine half shell are used to fasten the outer rings of the first rolling bearing and the second rolling bearing.

[0013] Furthermore, the spring support lever includes a spring support lever shaft, an upper spring support lever head, and a lower spring support lever head. The upper end of the spring support lever shaft is inserted into the first end of the upper spring support lever head. The second end of the upper spring support lever head is hingedly connected to the slider. The first end of the lower spring support lever head is hingedly connected to the swing lever. The second end of the lower spring support lever head is connected to the lower end of the spring support lever shaft. The balancing device further includes a first compression spring fitted around the outer periphery of the spring support lever shaft. The first compression spring is interposed between the upper spring support lever head and the lower spring support lever head.

[0014] Furthermore, the balance device further includes an upper spring support lever bearing, a lower spring support lever bearing, a first hinge connection shaft, and a second hinge connection shaft. The second end of the upper spring support lever head and the slider are hinge-connected by the first hinge connection shaft. The inner ring of the upper spring support lever bearing is fitted on the outer periphery of the first hinge connection shaft, and the outer ring of the upper spring support lever bearing is fitted on the second end of the upper spring support lever head. The first end of the lower spring support lever head and the swing lever are hinge-connected by the second hinge connection shaft. The inner ring of the lower spring support lever bearing is fitted on the outer periphery of the second hinge connection shaft, and the outer ring of the lower spring support lever bearing is fitted on the first end of the lower spring support lever head.

[0015] Furthermore, the spring support lever shaft includes a bolt with a head. The upper spring support lever head has a first stepped hole provided therethrough. The bolt head of the bolt with a head is movably inserted into the first stepped hole. The bolt lever of the bolt with a head is connected to the lower spring support lever head. When the distance between the upper spring support lever head and the lower spring support lever head is maximum, the bolt head of the bolt with a head abuts against the stepped surface of the first stepped hole.

[0016] Furthermore, the bolt with a head includes a reamer bolt. The screw lever of the reamer bolt is connected to the lower spring support lever head.

[0017] Furthermore, the spring support lever includes a socket and a plug. The first end of the socket is hinge-connected to the swing lever. The first end of the plug is inserted into the second end of the socket. The second end of the plug is hinge-connected to the slider. The balance device further includes a second compression spring fitted on the outer periphery of the spring support lever. The second compression spring is interposed between the socket and the plug.

[0018] Furthermore, the spring support lever further includes a stopper connected to the first end of the plug. The plug includes a connected plug lever and a plug head. The first end of the socket is hingedly connected to the swing lever. The second end of the socket has a second stepped hole. The plug lever is movably inserted into the second stepped hole. The second end of the plug head is hingedly connected to the slider. When the distance between the plug head and the socket is maximum, the stopper abuts against the stepped surface of the second stepped hole. When the distance between the plug head and the socket is minimum, the plug head abuts against the socket.

[0019] Furthermore, the swing lever includes a connected connecting portion and a bearing fork. The bearing fork includes two bearing fork arms provided on both sides of the roller respectively. The traction device is connected to one of the bearing fork arms. The roller has a roller shaft. One end of the roller shaft is rotatably connected to the bearing fork. The output end of the traction device is drivingly connected to the other end of the roller shaft.

[0020] Furthermore, the electric auxiliary drive device further includes a swing lever bearing shaft. The mounting bracket and the second end of the swing lever are hingedly connected by the swing lever bearing shaft. The spring support lever is movably provided between the roller and the swing lever bearing shaft. The swing lever further includes a web. The two bearing fork arms are connected by one side of the web. The other side of the web is connected to the connecting portion. The connecting portion has a groove provided obliquely downward. The first end of the spring support lever is inserted into the groove. A stopper is provided on the mounting bracket. The stopper abuts against the bearing fork to limit the rotation angle of the swing lever.

[0021] According to another aspect of the present application, a hospital bed is provided. The hospital bed includes a bed body and an electric auxiliary drive device. The mounting bracket of the electric auxiliary drive device is connected to the bed body. The electric auxiliary drive device includes the electric auxiliary drive device provided above.

Advantages of the Invention

[0022] Applying the technical means of the present application, the electric auxiliary driving device includes a mounting bracket, a swing lever, a traction device, a lifting device and a balance device. The mounting bracket is fixedly connected to the furniture, and the driving device is used to drive the slider to extend linearly along the mounting bracket, and further drive the spring support lever to rotate by the slider, and drive the rotation of the swing lever by the spring support lever, and make the roller contact the ground, and further drive the rolling of the roller by the traction device, that is, use the electric auxiliary driving device to move the furniture, and further reduce the pressure when the operator moves the furniture. Since the lifting device and the balance device are connected by using a linearly moving slider, the slider moves linearly along the horizontal direction, and further, the lifting function of the electric auxiliary driving device can be realized in a very small mounting space, and all other parts of the electric auxiliary driving device are located below the mounting bracket, thereby reducing the mounting space in the height direction.

Brief Description of the Drawings

[0023] The drawings in the specification constituting a part of the present application are used to provide a further understanding of the present application. The exemplary embodiments of the present application and their descriptions are used to interpret the present application and do not limit the present application improperly. In the drawings,

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

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Figure 14

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Figure 18

[0024] Here, the above drawings include the following reference numerals. 10... mounting bracket, 11... swing lever bearing shaft, 12... guide groove, 14... shell, 20... Oscillating lever, 21... Roller, 22... Roller shaft, 23... Groove, 24... Bearing fork, 25... Web, 30... Lifting device, 31... Driving motor, 32... Worm, 33... Turbine, 33.1... Second screw hole, 33.2... External teeth, 33.3... First rolling bearing, 33.4... Second rolling bearing, 34... Turbine shell, 34.1... First turbine half shell, 34.2... Second turbine half shell, 35... Second main shaft, 37... Shift cam ring, 38... First limit switch, 39... Second limit switch, 40... Balancing device, 41... Upper spring support lever bearing, 42... Lower spring support lever bearing, 43... Spring support lever, 43.1... Upper spring support lever head, 43.2... Lower spring support lever head, 43.3... Spring support lever shaft, 43.4... First compression spring, 44... Slider, 44.1... Linear guide rail, 44.2... Bush, 44.3... Fixed hole, 45... Socket, 46... Plug, 46.1... Plug lever, 46.2... Plug head, 47... Stopper, 50... Traction device, 51... Third gear motor.

Embodiments for Carrying out the Invention

[0025] Hereinafter, with reference to the drawings in the embodiments of the present application, the technical means in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Hereinafter, the description of at least one exemplary embodiment is only illustrative in nature and is not used as any limitation to the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained on the premise that those skilled in the art do not perform creative labor all belong to the protection scope of the present application.

[0026] As shown in FIGS. 1 to 10, Embodiment 1 of the present application provides an electric assist drive device, which includes a mounting bracket 10, a swing lever 20, a traction device 50, a lifting device 30, and a balance device 40. The mounting bracket 10 is fixedly connected to the furniture, a rotatable roller 21 is provided at the first end of the swing lever 20, the second end of the swing lever 20 is hinged to the mounting bracket 10, the traction device 50 is connected to the swing lever 20, the traction device 50 is drivingly connected to the roller 21, the lifting device 30 includes a slider 44 that moves linearly along with the driving device, and the driving device drives the rotation of the swing lever 20 by driving the movement of the slider 44. The balance device 40 includes a spring support lever 43. The first end of the spring support lever 43 is hinged to the swing lever 20, and the second end of the spring support lever 43 is hinged to the slider 44.

[0027] Applying the technical means of the present application, the electric assist drive device includes a mounting bracket 10, a swing lever 20, a traction device 50, a lifting device 30, and a balance device 40. The mounting bracket 10 is fixedly connected to the furniture, and the driving device is used to drive the slider 44 to extend linearly along the mounting bracket 10. Further, the slider 44 drives the spring support lever 43 to rotate, and the spring support lever 43 drives the rotation of the swing lever 20, causing the roller 21 to contact the ground. Further, the traction device 50 drives the rolling of the roller 21, that is, the electric assist drive device is used to move the furniture, and further, the pressure on the operator when moving the furniture can be reduced. Since the slider 44 that moves linearly is used to connect the lifting device and the balance device, the slider 44 moves linearly along the horizontal direction, and in a very small mounting space, the lifting function of the electric assist drive device can be realized, and all other components of the electric assist drive device are placed below the mounting bracket 10, thereby reducing the mounting space in the height direction.

[0028] Moreover, the electric assist drive device of the present application is particularly applicable to the floors of hospitals and convalescent homes, and is added to a mobile hospital bed firmly supported by at least three or more casters. In the above arrangement, since the fixed casters cannot guarantee permanent contact with the ground, in addition to the lifting device 30 for temporarily lowering and raising the roller 21, it also has one balance device 40 for maintaining continuous contact between the roller 21 and the ground.

[0029] In this embodiment, the upper surface of the mounting bracket 10 is fixedly connected to the lower surface of the furniture, the swing lever 20 is located in the rear region below the mounting bracket 10, the traction device 50 is located on one side of the swing lever 20 and is connected to the side of the swing lever 20, and the lifting device 30 is located in the front region below the mounting bracket 10. Adopting the above structural arrangement method, after the roller 21 is retracted, it can be completely located in the rear region below the mounting bracket 10. In addition to the thickness of the furniture bottom plate or the height of the support at the top of the mounting bracket 10, after the roller 21 is retracted, the minimum height of the electric assist drive device in the present application is completely determined by the diameter of the roller 21. Therefore, a relief groove into which the roller is snapped can be designed in the central region of the mounting bracket 10, and in this way, the minimum height of the electric assist drive device can be made to correspond to the diameter of the roller 21.

[0030] Note that by using the lifting device 30, the swing lever 20 can first rotate downward around its hinge connection point with the mounting bracket 10 so as to easily bring the roller 21 into contact with the ground when it enters its driving position. Thereafter, the balance device 40 can compensate for the unevenness of the ground from this position, for example, the protrusions and depressions of the ground, so as to keep the roller 21 always in contact with the ground.

[0031] As shown in FIGS. 2 and 5, the balance device 40 further includes a guide structure. The guide structure extends along a straight line and includes a guide element and a guide groove 12. The guide element is inserted into the guide groove 12. The guide groove 12 is provided in one of the mounting bracket 10 or the slider 44, and the guide element is provided in the other of the mounting bracket 10 or the slider 44. The guide structure can be used to form a guiding action on the slider 44, and the slider 44 can be moved along the extending direction of the guide structure, and the slider 44 is not deflected, thereby ensuring the normal operation of the balance device 40 and the swing lever 20.

[0032] As shown in FIGS. 4 and 5, the guide element includes a linear guide rail 44.1 provided on the side wall of the slider 44. Two parallel guide plates are provided on the side wall of the mounting bracket 10. The space between the two guide plates surrounds the guide groove 12. The guide element and the guide groove 12 adopting the above structure have the advantages of simple structure and easy processing.

[0033] In other embodiments, the guide element includes a linear guide rail 44.1 provided on the bottom wall of the slider 44. Two parallel guide ribs are provided on the bottom wall of the mounting bracket 10. The space between the two guide ribs surrounds the guide groove 12. The above structure is adopted, which has the advantages of simple structure and easy processing.

[0034] In this embodiment, the driving device includes a driving motor 31 and a second main shaft 35 drivingly connected to the driving motor 31. The second main shaft 35 is connected to the slider 44 and drives the slider 44 to move along a straight line. The driving device adopting the above structure drives the second main shaft 35 by using the driving motor 31, and drives the slider 44 to move along a straight line by the second main shaft 35, and has the advantage that the driving structure and the transmission structure are simple.

[0035] Specifically, a bush 44.2 is provided at the second end of the slider 44, a fixing hole 44.3 is provided in the bush 44.2, the first end of the second spindle 35 is inserted into the bush 44.2, and is inserted into the fixing hole using a fixing pin, connecting the second spindle 35 and the slider 44.

[0036] In other embodiments, the drive device includes a first gear motor and a first spindle. The first gear motor drives the rotation of the first spindle. The first spindle has a male thread, and a first threaded hole is provided in the slider 44. The male thread is screwed into the first threaded hole. By adopting the above structure, the rotational movement of the first spindle can be converted into the linear movement of the slider 44, which has the advantage of a simple structure.

[0037] As shown in FIGS. 8 and 9, the lifting device 30 further includes a turbine 33 and a worm 32 that are relatively rotatable and cooperate with each other. The drive motor 31 includes a second gear motor. The output end of the second gear motor is drivingly connected to the worm 32. The teeth of the worm 32 mesh with the external teeth 33.2 of the turbine 33. The turbine 33 has a second threaded hole 33.1. The second spindle 35 is drilled through the second threaded hole 33.1 and screwed into the turbine 33. By the cooperation of the turbine 33 and the worm 32, the rotational movement of the output shaft of the gear motor can be converted into the linear movement of the second spindle 35, which has the advantages of a simple transmission structure and high reliability.

[0038] In this embodiment, a shift cam ring 37 is fitted at the second end of the second spindle 35. By alternately cooperating the shift cam ring 37 with the first limit switch 38 or the second limit switch 39, the extension or retraction of the second spindle 35 is realized.

[0039] Specifically, under the control of the electronic module, the drive motor 31 drives the second main shaft 35 to extend relative to the mounting bracket 10. At the same time, the second main shaft 35 moves the slider 44, and the slider 44 rotates the swing lever 20 via the spring support lever 43. When the swing lever 20 rotates, the roller 21 contacts the ground. At this time, the shift cam ring 37 abuts against the first limit switch 38, and the second main shaft 35 stops extending and is fixed so as not to move. When it is necessary to retract the roller 21, under the control of the electronic module, the drive motor 31 drives the second main shaft 35 to retract relative to the mounting bracket 10, and further rotates the swing lever 20 in the reverse direction via the spring support lever 43. When the swing lever 20 rotates, the roller 21 is retracted at the same time.

[0040] As shown in FIGS. 8 and 9, the lifting device 30 further includes a turbine shell 34 fixedly connected to the mounting bracket 10. The turbine 33 is provided in the turbine shell 34. The turbine shell 34 can be used to protect the turbine 33 and the worm 32, avoiding the influence on the turbine 33 and the worm 32 during the transmission process, and further improving the transmission accuracy.

[0041] In this embodiment, the lifting device 30 further includes a first rolling bearing 33.3 and a second rolling bearing 33.4. The turbine shell 34 includes a connected first turbine half shell 34.1 and a second turbine half shell 34.2. The inner rings of the first rolling bearing 33.3 and the second rolling bearing 33.4 are respectively fitted at both ends of the turbine 33. The first turbine half shell 34.1 and the second turbine half shell 34.2 are used to fasten the outer rings of the first rolling bearing 33.3 and the second rolling bearing 33.4. By adopting the first rolling bearing 33.3 and the second rolling bearing 33.4, a centering effect can be formed on the turbine 33, and the rotation process of the turbine 33 can be made smoother.

[0042] Specifically, a shell 14 is further connected to the bottom wall of the mounting bracket 10, and the drive motor 31, the turbine 33, and the worm 32 are all located within the space surrounded by the mounting bracket 10 and the shell 14. And when the roller is in the retracted position, the second main shaft 35 is also located within the space surrounded by the mounting bracket 10 and the shell 14. The shell 14 can be used to form a protection for the above components.

[0043] As shown in FIGS. 5 to 9, the spring support lever 43 includes a spring support lever shaft 43.3, an upper spring support lever head 43.1, and a lower spring support lever head 43.2. The upper end of the spring support lever shaft 43.3 is inserted into the first end of the upper spring support lever head 43.1. The second end of the upper spring support lever head 43.1 is hinge-connected to the slider 44. The first end of the lower spring support lever head 43.2 is hinge-connected to the swing lever 20. The second end of the lower spring support lever head 43.2 is connected to the lower end of the spring support lever shaft 43.3. The spring support lever 43 adopting the above structure can form a sliding action on the upper spring support lever head 43.1 by using the spring support lever shaft 43.3, and can further adapt to the depressions or protrusions on the ground, thereby keeping the roller 21 always in contact with the ground and improving the usage range of the electric auxiliary drive device.

[0044] In this embodiment, the balance device 40 further includes a first compression spring 43.4 fitted on the outer periphery of the spring support lever shaft 43.3. The first compression spring 43.4 is interposed between the upper spring support lever head 43.1 and the lower spring support lever head 43.2. The first compression spring 43.4 can be used to form a buffering action. When the roller 21 encounters a depression or a protrusion on the ground, the elastic force of the spring can quickly move the spring support lever 43 within the upper spring support lever head 43.1 and the lower spring support lever head 43.2, and can further quickly rotate the swing lever 20 to respond, thereby keeping the roller 21 always in close contact with the ground.

[0045] Note that the balance device 40 further includes an upper spring support lever bearing 41, a lower spring support lever bearing 42, a first hinge connection shaft, and a second hinge connection shaft. The second end of the upper spring support lever head 43.1 and the slider 44 are hinge-connected by the first hinge connection shaft. The inner ring of the upper spring support lever bearing 41 is fitted on the outer periphery of the first hinge connection shaft, and the outer ring of the upper spring support lever bearing 41 is fitted on the second end of the upper spring support lever head 43.1. The first end of the lower spring support lever head 43.2 and the swing lever 20 are hinge-connected by the second hinge connection shaft. The inner ring of the lower spring support lever bearing 42 is fitted on the outer periphery of the second hinge connection shaft, and the outer ring of the lower spring support lever bearing 42 is fitted on the first end of the lower spring support lever head 43.2. The balance device 40 adopting the above structure can make the rotation of the upper spring support lever head 43.1 and the lower spring support lever head 43.2 smoother.

[0046] In this embodiment, the spring support lever shaft 43.3 includes a headed bolt. The upper spring support lever head 43.1 has a first stepped hole provided therethrough. The bolt head of the headed bolt is movably inserted into the first stepped hole. The bolt lever of the headed bolt is connected to the lower spring support lever head 43.2. When the distance between the upper spring support lever head 43.1 and the lower spring support lever head 43.2 is maximum, the bolt head of the headed bolt abuts against the stepped surface of the first stepped hole. Forming the spring support lever shaft 43.3 by using a headed bolt has the advantages of easy material taking and low cost.

[0047] Specifically, the headed bolt includes a reamer bolt. The screw lever of the reamer bolt is connected to the lower spring support lever head 43.2. By adopting the above structure, a fixed end can be formed at the lower end of the reamer bolt, and a moving end can be formed at the upper end, which facilitates the movement of the reamer bolt within the upper spring support lever head 43.1, thereby realizing the guidance for the swing lever 20.

[0048] As shown in Fig. 5, when the roller 21 is in the retracted position, the second main shaft 35 is at the tip position of the mounting bracket 10, and the upper spring support head 43.1 is located at a position approaching the turbine 33 together with the slider 44. At this time, the distance between the upper spring support lever head 43.1 and the lower spring support lever head 43.2 is the largest, the spring support lever shaft 43.3 abuts against the step surface of the first stepped hole, and the swing lever 20 is located at a position where its first end approaches the mounting bracket 10 together with the spring support lever 43, forming a restraining action on the swing lever 20, thereby retracting the roller 21.

[0049] As shown in Fig. 6, when the electric auxiliary drive device operates, the drive motor 31 is used to rotate the worm 32, and the worm 32 rotates the turbine 33, further driving the second main shaft 35 to move to the rear end of the mounting bracket 10. The second main shaft 35 moves the slider 44 along the extending direction of the guide structure, and further the slider 44 moves the upper spring support lever head 43.1 linearly. Under the elastic force action of the first compression spring 43.4, the spring support lever 43 rotates the swing lever 20, thereby bringing the roller 21 into contact with the ground. At the same time, the traction device drives the rotation of the roller 21, and further the electric auxiliary drive device can move the furniture. At this time, the first compression spring 43.4 is in a compressed state.

[0050] As shown in Fig. 7, when the roller 21 encounters a ground protrusion, the roller 21 moves upward and further rotates the swing lever 20 upward. Since the spring support lever shaft 43.3 is connected to the lower spring support lever head 43.2, the upper end of the spring support lever shaft 43.3 moves upward along the upper spring support lever head 43.1 until it abuts against the first hinge connection shaft, forming an upper limit for the upper end of the spring support lever shaft 43.3. At this time, the first compression spring 43.4 is in a compressed state, and since the spring support lever shaft 43.3 cannot continue to move upward, the swing lever 20 cannot move the roller 21 upward either. The maximum height of the ground protrusion that the roller 21 can compensate for is 20 mm.

[0051] As shown in FIG. 8, when the roller 21 encounters a ground depression, the roller 21 moves downward and further rotates the swing lever 20 downward. Since the spring support lever shaft 43.3 is connected to the lower spring support lever head 43.2, the upper end of the spring support lever shaft 43.3 moves downward along the upper spring support lever head 43.1 until it abuts against the step surface of the first stepped hole, forming the lower limit of the spring support lever shaft 43.3. At this time, since the spring support lever shaft 43.3 cannot continue to move downward, the swing lever 20 cannot move the roller 21 downward either. The maximum height of the ground depression that the roller 21 can compensate for is 20 mm.

[0052] Here, in this embodiment, the maximum height of the ground depression or protrusion that the roller 21 can compensate for is 20 mm. Of course, the actual compensation value can be changed according to parameters such as the distance between the limit switches, the extension length of the spring support lever 43, or the mounting position of the auxiliary drive device.

[0053] In addition, when the auxiliary drive device requires the operator to reduce the pressure, the second main shaft 35 is always in a state of extending with respect to the rear end of the mounting bracket 10.

[0054] Also, an additional vertical axis can be designed to steer the roller 21. Of course, the auxiliary drive device may have one or more rollers. For example, two parallel and spaced rollers 21 can be designed, each roller 21 having a single motor, or two auxiliary drivers can be provided at intervals as a pair, and by controlling the motor located on the outer side of the curve to rotate faster than the other motor, the steering turning can also be realized.

[0055] Note that all types of motors can be regarded as the drive motor 31. A gear motor with a turbine 33 is preferred. Note that a brushless DC motor type gearless motor may also be used.

[0056] As shown in Fig. 4, the swing lever 20 includes a connected connection part and a bearing fork 24. The bearing fork 24 includes two bearing fork arms provided on both sides of the roller 21 respectively. The traction device 50 is connected to one of the bearing fork arms. The roller 21 has a roller shaft 22. One end of the roller shaft 22 is rotatably connected to the bearing fork 24, and the output end of the traction device 50 is drivingly connected to the other end of the roller shaft 22. The swing lever 20 adopting the above structure has the advantages of simple connection structure and easy assembly. Moreover, by adopting the bearing fork 24 designed with two bearing fork arms, the force reception on both sides of the roller 21 can be made more uniform.

[0057] In this embodiment, the second end of the connection part is hingedly connected to the mounting bracket 10.

[0058] As shown in Figs. 4 and 5, the electric auxiliary drive device further includes a swing lever bearing shaft 11. The mounting bracket 10 and the second end of the swing lever 20 are hingedly connected by the swing lever bearing shaft 11. The spring support lever 43 is movably provided between the roller 21 and the swing lever bearing shaft 11. By adopting the swing lever bearing shaft 11, the mounting bracket 10 and the swing lever 20 can be hingedly connected, which has the advantage of simple structure.

[0059] Specifically, the swing lever 20 further includes a web 25. The two bearing fork arms are connected by one side of the web 25, and the other side of the web 25 is connected to the connection part. By adopting the web 25, the connection part and the bearing fork 24 can be connected, which has the advantage of simple connection structure.

[0060] In this embodiment, the connection part has a groove 23 provided obliquely downward, and the first end of the spring support lever 43 is inserted into the groove 23. By using the groove 23, a relief effect can be formed on the spring support lever 43, which has the advantage of being easy to provide.

[0061] Specifically, both the first end of the spring support lever shaft 43.3 and the lower spring support lever head 43.2 are located within the groove 23.

[0062] Here, a stopper is provided on the mounting bracket 10, and the stopper abuts against the bearing fork 24 so as to limit the rotation angle of the swing lever 20. By using the stopper, when the swing lever 20 is in the retracted position, a limiting action is formed on the swing lever 20, thereby protecting the roller 21.

[0063] In this embodiment, the traction device 50 includes a third gear motor 51, and the third gear motor 51 and the transmission device are arranged laterally on the left arm of the bearing fork 24. Thereby, the output of the third gear motor 51 directly acts on the roller shaft 22.

[0064] Embodiment 2 of the present application provides an electric auxiliary drive device. The difference between Embodiment 2 and Embodiment 1 is that in Embodiment 2, as shown in FIGS. 11 to 14, the spring support lever 43 includes a socket 45 and a plug 46. The first end of the socket 45 is hinged to the swing lever 20, the first end of the plug 46 is inserted into the second end of the socket 45, the second end of the plug 46 is hinged to the slider 44, and the matching method of the socket 45 and the plug 46 is adopted. The plug 46 can form a sliding action in the socket 45, and can further adapt to the depression or protrusion on the ground, thereby keeping the roller 21 in contact with the ground at all times and improving the use range of the electric auxiliary drive device.

[0065] In this embodiment, the balance device 40 further includes a second compression spring fitted on the outer periphery of the spring support lever 43, and the second compression spring is interposed between the socket 45 and the plug 46. By using the second compression spring, a buffering action can be formed. When the roller 21 encounters a depression or protrusion on the ground, the spring support lever 43 can be quickly moved within the upper spring support lever head 43.1 and the lower spring support lever head 43.2 by the elastic action of the spring, and the swing lever 20 can be quickly rotated to respond, thereby keeping the roller 21 in close contact with the ground at all times.

[0066] As shown in FIGS. 11 to 14, the spring support lever 43 further includes a stopper 47 connected to the first end of the plug 46. The plug 46 includes a connected plug lever 46.1 and a plug head 46.2. The first end of the socket 45 is hingedly connected to the swing lever 20. The second end of the socket 45 has a second stepped hole. The plug lever 46.1 is movably inserted into the second stepped hole. The second end of the plug head 46.2 is hingedly connected to the slider 44. When the distance between the plug head 46.2 and the socket 45 is maximum, the stopper 47 abuts against the stepped surface of the second stepped hole. When the distance between the plug head 46.2 and the socket 45 is minimum, the plug head 46.2 abuts against the socket 45. By adopting the above structure, a fixed end can be formed at the upper end of the plug lever 46.1 and a moving end can be formed at the lower end, which facilitates the movement of the plug lever 46.1 within the socket 45, thereby realizing the guidance for the swing lever 20.

[0067] As shown in FIG. 15, when the roller 21 is in the retracted position, the distance between the plug head 46.2 and the socket 45 is maximum, and the stopper 47 abuts against the stepped surface of the second stepped hole, thereby forming a restraining action on the swing lever 20 to retract the roller 21.

[0068] As shown in FIG. 16, when the electric auxiliary drive device operates, the roller 21 abuts against the ground, and the plug lever 46.1 moves within the socket 45 so as to be able to adapt to changes in the ground at any time.

[0069] As shown in FIG. 17, when the roller 21 encounters a ground protrusion, the distance between the plug head 46.2 and the socket 45 is minimum, and the plug head 46.2 abuts against the socket 45, thereby restricting the rotation angle of the swing lever 20 and enabling the roller 21 to compensate for the ground protrusion.

[0070] As shown in FIG. 18, when the roller 21 encounters a ground depression, the distance between the plug head 46.2 and the socket 45 is at its maximum, and the stopper 47 abuts against the step surface of the second stepped hole, thereby restricting the rotation angle of the swing lever 20 and enabling the roller 21 to compensate for the ground depression.

[0071] Example 3 of the present application provides a hospital bed, which includes a bed body and an electric auxiliary drive device. The mounting bracket of the electric auxiliary drive device is connected to the bed body, and the electric auxiliary drive device includes the above-provided electric auxiliary drive device. The hospital bed adopting the above electric auxiliary drive device connects the lifting device and the balance device by using a linearly moving slider 44. Therefore, the slider 44 linearly moves along the horizontal direction, and the lifting function of the electric auxiliary drive device can be realized within a very small mounting space. Moreover, all other components of the electric auxiliary drive device are placed below the mounting bracket 10, thereby reducing the mounting space in the height direction.

Claims

1. A mounting bracket (10) fixedly connected to the furniture, A swing lever (20) provided with a rotatable roller (21) at a first end and hinge-connected at a second end to the mounting bracket (10), A traction device (50) connected to the swing lever (20) and drivingly connected by the traction device (50) to the roller (21), A lifting device (30) including a slider (44) moving linearly along a driving device, the driving device driving the rotation of the swing lever (20) by driving the movement of the slider (44), A balance device (40) including a spring support lever (43), a first end of the spring support lever (43) being hinge-connected to the swing lever (20) and a second end of the spring support lever (43) being hinge-connected to the slider (44), characterized by an electric auxiliary driving device.

2. The balance device (40) further includes a guide structure extending linearly, the guide structure including a guide element and a guide groove (12), the guide element being inserted into the guide groove (12), the guide groove (12) being provided in one of the mounting bracket (10) or the slider (44), and the guide element being provided in the other of the mounting bracket (10) or the slider (44), the electric auxiliary driving device according to Claim 1, characterized in that.

3. The guide element includes a linear guide rail (44.1) provided on a side wall of the slider (44), two parallel guide plates being provided on the mounting bracket (10), a space between the two guide plates surrounding the guide groove (12), or, The guide element includes a linear guide rail (44.1) provided on a bottom wall of the slider (44), two parallel guide ribs being provided on the mounting bracket (10), a space between the two guide ribs surrounding the guide groove (12), the electric auxiliary driving device according to Claim 2, characterized in that.

4. The drive device includes a first gear motor and a first main shaft. The first gear motor drives the rotation of the first main shaft. The first main shaft has a male screw. A first screw hole is provided in the slider (44), and the male screw is screwed into the first screw hole. The electric auxiliary drive device according to claim 1, characterized in that.

5. The drive device includes a drive motor (31) and a second main shaft (35) drivingly connected to the drive motor (31). The second main shaft (35) is connected to the slider (44) and drives the slider (44) to move along a straight line. The electric auxiliary drive device according to claim 1, characterized in that.

6. The lifting device (30) further includes a turbine (33) and a worm (32) that are relatively rotatable and cooperate with each other. The drive motor (31) includes a second gear motor. The output end of the second gear motor is drivingly connected to the worm (32). The teeth of the worm (32) mesh with the external teeth (33.2) of the turbine (33). The turbine (33) has a second screw hole (33.1). The second main shaft (35) is drilled in the second screw hole (33.1) and screwed into the turbine (33). The electric auxiliary drive device according to claim 5, characterized in that.

7. The lifting device (30) further includes a turbine shell (34) fixedly connected to the mounting bracket (10). The turbine (33) is provided in the turbine shell (34). The lifting device (30) further includes a first rolling bearing (33.3) and a second rolling bearing (33.4). The turbine shell (34) includes a connected first turbine half shell (34.1) and a second turbine half shell (34.2). The inner rings of the first rolling bearing (33.3) and the second rolling bearing (33.4) are respectively fitted at both ends of the turbine (33). The first turbine half shell (34.1) and the second turbine half shell (34.2) are used to fasten the outer rings of the first rolling bearing (33.3) and the second rolling bearing (33.4). The electric auxiliary drive device according to claim 6, characterized in that.

8. The spring support lever (43) includes a spring support lever shaft (43.3), an upper spring support lever head (43.1), and a lower spring support lever head (43.2). The upper end of the spring support lever shaft (43.3) is inserted into the first end of the upper spring support lever head (43.1). The second end of the upper spring support lever head (43.1) is hinge-connected to the slider (44). The first end of the lower spring support lever head (43.2) is hinge-connected to the swing lever (20). The second end of the lower spring support lever head (43.2) is connected to the lower end of the spring support lever shaft (43.3). The balance device (40) further includes a first compression spring (43.4) fitted on the outer periphery of the spring support lever shaft (43.3), and the first compression spring (43.4) is interposed between the upper spring support lever head (43.1) and the lower spring support lever head (43.2). The electric auxiliary drive device according to claim 1, characterized in that.

9. The balance device (40) further includes an upper spring support lever bearing (41), a lower spring support lever bearing (42), a first hinge connection shaft, and a second hinge connection shaft. The second end of the upper spring support lever head (43.1) and the slider (44) are hinge-connected by the first hinge connection shaft. The inner ring of the upper spring support lever bearing (41) is fitted on the outer periphery of the first hinge connection shaft. The outer ring of the upper spring support lever bearing (41) is fitted on the second end of the upper spring support lever head (43.1). The first end of the lower spring support lever head (43.2) and the swing lever (20) are hinge-connected by the second hinge connection shaft. The inner ring of the lower spring support lever bearing (42) is fitted on the outer periphery of the second hinge connection shaft. The outer ring of the lower spring support lever bearing (42) is fitted on the first end of the lower spring support lever head (43.2). The electric auxiliary drive device according to claim 8, characterized in that.

10. The spring support lever shaft (43.3) includes a bolt with a head. The upper spring support lever head (43.1) has a first stepped hole provided therethrough. The bolt head of the bolt with a head is movably inserted into the first stepped hole. The bolt lever of the bolt with a head is connected to the lower spring support lever head (43.2). When the distance between the upper spring support lever head (43.1) and the lower spring support lever head (43.2) is maximum, the bolt head of the bolt with a head abuts against the stepped surface of the first stepped hole. The electric auxiliary drive device according to claim 9, characterized in that.

11. The bolt with a head includes a reamer bolt, and the screw lever of the reamer bolt is connected to the lower spring support lever head (43.2). The electric auxiliary drive device according to claim 10, characterized in that.

12. The spring support lever (43) includes a socket (45) and a plug (46). The first end of the socket (45) is hingedly connected to the swing lever (20). The first end of the plug (46) is inserted into the second end of the socket (45). The second end of the plug (46) is hingedly connected to the slider (44). The balance device (40) further includes a second compression spring fitted on the outer periphery of the spring support lever (43), and the second compression spring is interposed between the socket (45) and the plug (46). The electric auxiliary drive device according to claim 1, characterized in that.

13. The spring support lever (43) further includes a stopper (47) connected to the first end of the plug (46). The plug (46) includes a connected plug lever (46.1) and a plug head (46.2). The first end of the socket (45) is hingedly connected to the swing lever (20). The second end of the socket (45) has a second stepped hole. The plug lever (46.1) is movably inserted into the second stepped hole. The second end of the plug head (46.2) is hingedly connected to the slider (44). When the distance between the plug head (46.2) and the socket (45) is maximum, the stopper (47) abuts against the stepped surface of the second stepped hole. When the distance between the plug head (46.2) and the socket (45) is minimum, the plug head (46.2) abuts against the socket (45). The electric auxiliary drive device according to claim 12, characterized in that.

14. The swing lever (20) includes a connected connecting portion and a bearing fork (24). The bearing fork (24) includes two bearing fork arms provided on both sides of the roller (21) respectively. The traction device (50) is connected to one of the bearing fork arms. The roller (21) has a roller shaft (22). One end of the roller shaft (22) is rotatably connected to the bearing fork (24). The output end of the traction device (50) is drivingly connected to the other end of the roller shaft (22). The electric auxiliary drive device according to claim 1, characterized in that.

15. The electric auxiliary drive device further includes a swing lever bearing shaft (11). The mounting bracket (10) and the second end of the swing lever (20) are hingedly connected by the swing lever bearing shaft (11). The spring support lever (43) is movably provided between the roller (21) and the swing lever bearing shaft (11). The swing lever (20) further includes a web (25). The two bearing fork arms are connected by one side of the web (25). The other side of the web (25) is connected to the connecting portion. The connecting portion has a groove (23) provided obliquely downward. The first end of the spring support lever (43) is inserted into the groove (23). A stopper is provided on the attachment bracket (10), and the stopper abuts against the bearing fork (24) so as to limit the rotation angle of the swing lever (20). The electric auxiliary drive device according to claim 14, characterized in that.

16. A bed body, An electric auxiliary drive device, wherein the attachment bracket of the electric auxiliary drive device is connected to the bed body, and the electric auxiliary drive device includes an electric auxiliary drive device including the electric auxiliary drive device according to any one of claims 1 to 15. A hospital bed, characterized by comprising:

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