Linkage mechanisms, linkage systems, linear actuators, and body support devices

Abstract

To provide a compact link mechanism which has a high extension ratio, which enables a multipoint stop, and which makes an installation space small.SOLUTION: A link mechanism 1 capable of being wound and extended comprises at least four links 11, 12, 13 and 14 that are connected in series in a mutually rotatable manner, and at least two connection rods 21 and 22 for alternately connecting the links together. The connection rods 21 and 22 diagonally cross the link between the links to be connected, and rotatably connect the links to be connected. The connection rods 21 and 22 are arranged almost in parallel with each other when the links are linearly extended.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a link mechanism, a link system, a linear actuator, and a body support device.

Background Art

[0002] A linear actuator is a mechanism that creates linear motion. Conventional linear actuators such as hydraulic cylinders and pneumatic cylinders essentially generate linear motion. On the other hand, an electric linear actuator converts rotational motion into linear motion by means of a lead screw mechanism. Such linear actuators are used in a wide range of fields such as robots, automation, and industrial applications.

[0003] Conventional linear actuators have a problem of a low elongation ratio. Here, the elongation ratio refers to the ratio of the length (L) when the actuator is fully extended to the length (l) when it is fully contracted. In conventional linear actuators, this elongation ratio is less than 2 (L < 2l). That is, in this case, the stroke length of the actuator is shorter than the original length of the actuator. The fundamental reason why conventional linear actuators cannot obtain a high elongation ratio is that they use a hard piston that cannot be bent or deformed.

[0004] In contrast, some electric linear actuators have a compact size while possessing a mechanical mechanism with a high extension ratio. These actuators are called telescopic linear actuators, and one example is the rigid chain actuator (see, for example, Non-Patent Document 1). This is a special type of mechanical telescopic linear actuator used in push-pull-lift applications. A rigid chain actuator consists of a multi-joint chain that forms an extendable member for transmitting traction force, and a rotating pinion device. The links of the multi-joint chain, which is the actuator, are connected so that they bend from a straight line in only one direction. When the pinion rotates, the chain links rotate 90 degrees within the housing that guides and fixes the chain. This forms a support column with rigidity that can withstand compression (buckling) and tension. In this way, the multi-joint chain (actuator) is wound and housed compactly and tightly.

[0005] An improved version of the rigid chain actuator is the zip chain actuator, which connects two zipper-like articulated chains to form a single powerful support column capable of pushing and pulling at speeds of up to 1000 mm / s (see, for example, Non-Patent Document 2).

[0006] Other examples of telescopic linear actuators with high extension ratios include spiral lifts (see, e.g., Non-Patent Document 3) and helical band actuators (see, e.g., Patent Document 1). These are the most compact electric linear actuators, consisting of a system that "deploys" metal bands that move horizontally and vertically to lift loads. Integrating spiral lifts into robots expands the robot's effective working space and enables compact and easy transport (see, e.g., Non-Patent Document 4). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent No. 4875660 [Non-patent literature]

[0008] [Non-Patent Document 1] "Basics of rigid-chain actuators" May 24, 2016, LINIEAR MOTION TIPS, A Design World Resource,https: / / www.linearmotiontips.com / basics-rigid-chain-actuators / [Non-Patent Document 2] “Zip Chain Actuators” Tsubakimoto Europe BVhttps: / / tsubaki.eu / products / mechanical-components / zip-chain-actuators / [Non-Patent Document 3] “Spiralift” PACO Grouphttp: / / www.pacospiralift.com / [Non-Patent Document 4] “Design of a spherical robot arm with the spiral zipper prismatic joint” F. Collins and M. Yim, 2016 IEEE International Conference on Robotics and Automation (ICRA), pp. 2137.2143. May 2016 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] Many conventional linear actuators have a low extension ratio, typically less than twice the size of the original actuator. Furthermore, these linear actuators require a large installation space relative to their stroke length. In addition, their weight increases exponentially as the stroke length increases. Moreover, many pneumatic and hydraulic linear actuators only have two-point mounting capabilities and cannot achieve intermediate positions.

[0010] Furthermore, even the telescopic linear actuators described above, which offer a high extension ratio in a compact installation space, have limitations as well as advantages. In the case of rigid chain actuators, the articulated chain is compactly stored and can be deployed at high speed (1000 mm / s). However, a drawback of this mechanism is that it cannot withstand forces acting perpendicular to the extension axis. This is because such forces bend the articulated chain, causing it to fold when it is stored. Zip chain actuators solve this problem by having two articulated chains work together to form a highly rigid support that restrains all axes, and by operating it at high speed. However, this actuator has the disadvantage of requiring more installation space because it needs two articulated chains to restrain all axes.

[0011] Spiral lifts and helical band actuators can operate in a smaller installation space compared to existing telescopic linear actuators. However, when extending spiral lifts and helical band actuators, despite their high extension ratio, they have the disadvantage of operating at a slower speed (maximum of about 10 mm / s) compared to conventional direct-drive actuators such as rigid chain actuators. This is due to the speed constraints of the interlock process, which involves rotating a metal band spirally to form a tube. On the other hand, this mechanism has all axes constrained, allowing it to resist forces at any extension point.

[0012] This disclosure is made in view of these circumstances, and its purpose is to provide a compact link mechanism and linear actuator that have a high extension ratio, are capable of multi-point stopping, and require little installation space. [Means for solving the problem]

[0013] To solve the above problems, a link mechanism according to one aspect of the present invention is a link mechanism that can be wound up and extended, comprising at least four links rotatably connected in series with respect to each other, and at least two connecting rods that connect every other link. The connecting rods diagonally cross the links between the links to be connected, thereby rotatably connecting the links to be connected. The connecting rods are arranged substantially parallel to each other when the links are extended in a straight line.

[0014] According to this embodiment, a compact link mechanism can be provided that has a high extension ratio, enables multi-point stopping, and requires minimal installation space.

[0015] Another aspect of the present invention is a link system. This link system comprises the link mechanism described above and a storage section for storing the wound-up link.

[0016] According to this embodiment, it is possible to provide a compact link system that has a high extension ratio, enables multi-point stopping, and requires little installation space, and that can store the wound-up link.

[0017] Yet another aspect of the present invention is a linear actuator. This linear actuator comprises the link mechanism described above and a power mechanism for winding and extending the link.

[0018] According to this embodiment, a compact linear actuator can be provided that has a high extension ratio, is capable of multi-point stopping, and requires little installation space.

[0019] Yet another aspect of the present invention is a body assist device. This body assist device comprises the link mechanism described above.

[0020] According to this aspect, it is possible to provide a compact body support device with a high elongation ratio, capable of multi-point stopping, and having a small installation space.

[0021] In addition, any combination of the above components, as well as those obtained by converting the expressions of the present disclosure among methods, devices, systems, recording media, computer programs, etc., are also effective as aspects of the present disclosure.

Effects of the Invention

[0022] According to the present disclosure, it is possible to provide a compact link mechanism and linear actuator with a high elongation ratio, capable of multi-point stopping, and having a small installation space.

Brief Description of the Drawings

[0023] [Figure 1] It is a schematic diagram showing a state where the links of the link mechanism according to the first embodiment are extended linearly. [Figure 2] It is a schematic diagram showing the shapes of various links of the link mechanism according to the first embodiment. [Figure 3] It is a schematic diagram showing the shapes of various links of the link mechanism according to the first embodiment. [Figure 4] It is a schematic diagram showing a state where the links of the link mechanism according to the first embodiment are extended linearly. [Figure 5] It is a schematic diagram showing a state where the links of the link mechanism according to the first embodiment are wound in a curved shape. [Figure 6] It is a schematic diagram of a link system according to the second embodiment. [Figure 7] It is a perspective side view of a link system according to the third embodiment. [Figure 8] It is a perspective perspective view of a link system according to the third embodiment. [Figure 9] It is a side view showing a state when the links of the link system according to the third embodiment are extended. [Figure 10]This is a perspective side view of the link system according to the third embodiment. [Figure 11] This is a side view of the link system according to the third embodiment. [Figure 12] This is a perspective view of the link system according to the third embodiment. [Figure 13] This is a front view of the link system according to the third embodiment. [Figure 14] This is a side view showing the state when the link of the link system according to the third embodiment is extended. [Figure 15] This is a schematic diagram showing the links used in the link system according to the fourth embodiment. [Figure 16] This is a perspective side view of a linear actuator according to the fifth embodiment. [Figure 17] This is a perspective view of a linear actuator according to the fifth embodiment. [Figure 18] This is a front view of a linear actuator according to a fifth embodiment. [Figure 19] This is a side view showing the state when the link of the linear actuator according to the fifth embodiment is extended. [Figure 20] This is a schematic diagram showing the process of a user wearing a physical support device according to the sixth embodiment, from a seated position to standing up. [Figure 21] This is a side view showing a user seated while wearing the physical support device according to the sixth embodiment. [Figure 22] This is a side view showing a user standing up while wearing the physical support device according to the sixth embodiment. [Figure 23] This is a side view of a physical support device according to the sixth embodiment. [Figure 24] This is a front view of a body support device according to the sixth embodiment. [Figure 25] This is a side view of the link mechanism of the body support device according to the sixth embodiment when it is fully retracted. [Figure 26]This is a front view of the link mechanism of the body support device according to the sixth embodiment when it is fully retracted. [Figure 27] This is a photograph taken from the front when a user is wearing the body support device according to the sixth embodiment on the left side of their body. [Figure 28] This is a photograph taken from the left side when a user is wearing the body support device according to the sixth embodiment on the left side of their body. [Figure 29] These are photographs taken from the side of two prototypes of a body support device according to the sixth embodiment. [Figure 30] These are frontal photographs of two prototypes of a body support device according to the sixth embodiment. [Figure 31] This is a schematic diagram showing how the body support device according to the sixth embodiment assists a user in moving from a seated position to a standing position and then walking from a standing position. [Modes for carrying out the invention]

[0024] The present invention will be described below with reference to the drawings, based on preferred embodiments. In embodiments and modifications, the same or equivalent components and members will be denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. In addition, the dimensions of the members in each drawing will be enlarged or reduced as appropriate to facilitate understanding. Furthermore, some members that are not important for explaining the embodiments will be omitted in each drawing. In addition, terms including ordinal numbers such as "first," "second," etc., are used to describe various components, but these terms are used only to distinguish one component from others, and the components are not limited by these terms.

[0025] [First Embodiment] Figure 1 shows a link mechanism 1 according to the first embodiment. Figure 1 shows the links constituting the link mechanism 1 extended in a straight line. The link mechanism 1 comprises four links, namely a first link 11, a second link 12, a third link 13, and a fourth link 14. The link mechanism 1 further comprises two connecting rods, namely a first connecting rod 21 and a second connecting rod 22.

[0026] In the example shown in Figure 1, the first link 11 is I-shaped. The second link 12, third link 13, and fourth link 14 are T-shaped. The first connecting rod 21 and second connecting rod 22 are I-shaped. Through holes are provided near both ends and near the center of the first link 11. Through holes are also provided near both ends of the first connecting rod 21 and second connecting rod 22. Through holes are also provided near both ends of the two rods that make up the T-shape of the second link 12, third link 13, and fourth link 14, and near where these two rods intersect. By overlapping each link and each connecting rod and aligning their through holes, and passing a connecting pin through the aligned through holes, each link and each connecting rod can be pivotally connected to each other so that they can rotate relative to one another.

[0027] The first link 11 and the second link 12 are pivotally connected at the through hole 105. The second link 12 and the third link 13 are pivotally connected at the through hole 106. The third link 13 and the fourth link 14 are pivotally connected at the through hole 107. The first link 11 and the first connecting rod 21 are pivotally connected at the through hole 101. The third link 13 and the first connecting rod 21 are pivotally connected at the through hole 103. The second link 12 and the second connecting rod 22 are pivotally connected at the through hole 102. The fourth link 14 and the second connecting rod 22 are pivotally connected at the through hole 104. In other words, the first link 11 and the third link 13 are connected via the first connecting rod 21. Similarly, the second link 12 and the fourth link 14 are connected via the second connecting rod 22.

[0028] The first connecting rod 21 diagonally crosses the second link 12, which is located between the first link 11 and the third link 13, connecting the first link 11 and the third link 13. The second connecting rod 22 diagonally crosses the third link 13, which is located between the second link 12 and the fourth link 14, connecting the second link 12 and the fourth link 14. In other words, the connecting rods diagonally cross the links between the links to be connected, rotatably connecting the links to be connected.

[0029] The first connecting rod 21 and the second connecting rod 22 are arranged approximately parallel to each other. That is, when the link is extended in a straight line, the connecting rods are arranged approximately parallel to each other.

[0030] In the example shown in Figure 1, the first connecting rod 21 is positioned on the back side of each link when viewed from the perspective of someone looking at the page. On the other hand, the second connecting rod 22 is positioned on the front side of each link when viewed from the perspective of someone looking at the page.

[0031] In the example shown in Figure 1, the first link 11 was I-shaped, the second link 12, third link 13, and fourth link 14 were T-shaped, and the first connecting rod 21 and second connecting rod 22 were I-shaped. However, these shapes are not limited to those shown above. The first link may have any suitable shape as long as through holes are provided near both ends and near the center in the direction perpendicular to the direction in which the link mechanism 1 extends linearly. Figure 2 schematically shows examples of first links of various shapes. Figure 2(a) shows a T-shaped link, and Figure 2(b) shows a D-shaped link. Similarly, the second, third, and fourth links may have any suitable shape as long as through holes are provided near both ends and near the center of the ends in the direction perpendicular to the direction in which the link mechanism 1 extends linearly. Figure 3 schematically shows examples of second, third, and fourth links of various shapes. Figure 3(a) shows a triangular link, and Figure 3(b) shows a link with each side of the triangle curved.

[0032] Hereafter, a link mechanism consisting of four links and two connecting rods, as shown in Figure 1, will be referred to as a "unit link mechanism." By sequentially adding and connecting links and connecting rods to the unit link mechanism, a longer link mechanism can be realized.

[0033] Figures 4 and 5 schematically show link mechanism 2, which is a unit link mechanism with eight links and eight connecting rods added. Specifically, link mechanism 2 comprises a first link 11, a second link 12, a third link 13, a fourth link 14, a fifth link 15, a sixth link 16, a seventh link 17, an eighth link 18, a ninth link 19, a tenth link 10a, an eleventh link 11a, a twelfth link 12a, a first connecting rod 21, a second connecting rod 22, a third connecting rod 23, a fourth connecting rod 24, a fifth connecting rod 25, a sixth connecting rod 26, a seventh connecting rod 27, an eighth connecting rod 28, a ninth connecting rod 29, and a tenth connecting rod 20a. Figure 4 shows link mechanism 2 extended in a straight line. Figure 5 shows the link mechanism 2 wound in a curved shape. In both Figures 4 and 5, the portion enclosed by the dotted line is the unit link mechanism.

[0034] As shown in Figure 4, the linearly extended link mechanism 2 can be wound up as follows. First, while fixing the first link 11 at the left end so that it does not move, a clockwise force is applied to the second link 12. In this case, the clockwise force is a force in the direction that increases the angle between the extension direction of the link mechanism 2 and the longitudinal direction of the connecting rod.

[0035] The second link 12 then attempts to rotate clockwise around the through hole 105. However, since link 12 is connected to the connecting rod 22, link 12 cannot rotate unless link 14 rotates clockwise. However, link 12a at the rightmost end of the 12th link can rotate clockwise because it is not connected to the link corresponding to the connecting rod 22 from the perspective of link 12. As a result, the 12th link 12a bends downward with respect to the extension direction of the link mechanism 2. When the 12th link 12a begins to rotate, link 11a also rotates slowly and with a lag via the connecting rod 20a directly connected to the 12th link. This lag in rotation occurs because the rotation angle of link 12a is always larger than the rotation angle of link 11a. The above movement can also be described as the 12th link 12a, the 11th link 11a, and the 10th link 10a rotating sequentially clockwise from the tip, with the vicinity of the through-hole 105 of the first link 11 being considered the "base".

[0036] The 12th link 12a can no longer rotate (bend) once it reaches the joint angle limit. For example, the joint angle is formed when the connecting shaft between the connecting rod 28 and link 10a in Figure 5 comes into contact with the connecting rod 20a.

[0037] In this way, each link rotates sequentially from the tip link until it reaches its joint angle limit. This allows the link mechanism 2 to be wound into a curved shape (a clockwise spiral in Figure 4) while the bending point is sequentially shifted towards the root. Links that have reached their rotation limit can be considered rigid in the bending direction.

[0038] Here's something to keep in mind: When starting to reel in, always secure the base link and apply force to the tip link. The direction of the applied force should be in the direction that increases the angle between the extension direction of the link mechanism and the longitudinal direction of the connecting rod (clockwise direction in Figure 4). Since the tip, bent to its joint angle limit, can be considered a rigid body, the force applied as described above can also be achieved by applying a torque in the winding direction to the tip of link mechanism 2. These are the three points. Even if a force is applied in the opposite direction to the above (counterclockwise in Figure 4), the link mechanism 2 will not move.

[0039] In Figure 5, the 12th link 12a to the 6th link 16 are fully wound up to the joint angle limit (i.e., rigid), the 5th link 15 to the 3rd link 13 are in the winding process, and the 2nd link 12 is extended (i.e., not bent).

[0040] As shown in Figure 5, the curved link mechanism 2 can be extended as follows. First, while fixing the extended links (in Figure 5, the 10th link 10a to the 12th link 12a) in place, a force in the direction of extension (counterclockwise in Figure 5) is applied to the links in the winding process.

[0041] Then the third link 13 begins to rotate counterclockwise. As the third link 13 begins to rotate, the fourth link 14, which is directly connected to the third link, and the fifth link 15, which is connected via the connecting rod 23, also rotate counterclockwise at an accelerating rate.

[0042] In this way, starting from the root link, each link rotates counterclockwise until it forms a straight line.

[0043] Here's something to keep in mind: When starting to extend, always secure the already extended link and apply force to the next link in the direction of extension. • When the link to which force has been applied becomes straight, apply force to the next link. To sequentially apply force to the next link, it is also possible to apply torque in the direction of extension (counterclockwise) to the tip of link mechanism 2, where the link has reached its joint angle limit. These are the three points.

[0044] If the components constituting each link and each connecting rod have sufficient rigidity, and there is no substantial looseness in the connections between each link and between each link and each connecting rod, the extended portion of the link mechanism can be considered a rigid body. Therefore, this link mechanism can be used in structures such as linear actuators and flexible trusses. Furthermore, since the wound portion of the link mechanism becomes spiral-shaped, a large extension ratio can be obtained. In addition, the link mechanism can be stopped and started at any point.

[0045] Thus, according to this embodiment, it is possible to provide a compact link mechanism with a high extension ratio, multi-point stopping capability, and small installation space.

[0046] [Second Embodiment] Figure 6 schematically shows a link system 200 according to a second embodiment. The link system 200 comprises a link mechanism 3 and a storage section 30 for housing the wound-up link. The link mechanism 3 includes an end pin 32. The storage section 30 includes a rotor 31. The rotor 31 includes a guide slot 34.

[0047] The link mechanism 3 is the one described in the above-mentioned embodiment.

[0048] The storage section 30 is a housing formed of any suitable material such as metal or plastic, and houses the wound-up portion of the links of the link system 200.

[0049] The rotor 31, located in the storage compartment 30, is rotatable clockwise and counterclockwise around its central axis. The rotor 31 is provided with five guide slots 33. The guide slots 33 engage appropriately with the end pins 32 provided in the link system 200 in terms of shape and position. As a result, when the rotor 31 rotates clockwise, the link system 200 is wound up, and when the rotor 31 rotates counterclockwise, the link system 200 is extended.

[0050] In the example shown in Figure 6, the link winding and unwinding mechanism uses five endpins and guide slots. However, it is not limited to this, and the number of endpins and guide slots can be any suitable number. Furthermore, the transmission mechanism for conveying rotational force and the power source are not limited to endpins and guide slots, but may, for example, be based on frictional force.

[0051] According to this embodiment, it is possible to provide a compact link system that has a high extension ratio, is capable of multi-point stopping, and requires little installation space, equipped with a link winding and extension mechanism, and capable of storing the wound-up link.

[0052] [Third Embodiment] (Example 1) The link system 201 according to the third embodiment will be described using Figures 7 to 9. Figure 7 is a perspective side view of the link system 201. Figure 8 is a perspective view of the link system 201. Figure 9 is a side view showing the state when the links of the link system 201 are extended.

[0053] The link system 201 comprises a link mechanism 4, a storage section 35 for storing the wound-up link, and two spur gears, namely spur gear 40a and spur gear 40b.

[0054] The link mechanism 4 is as described in the above-described embodiment. However, each link of the link mechanism 4 has a rack formed thereon that meshes with the spur gear 40a and the spur gear 40b.

[0055] The spur gears 40a and 40b are positioned near the exit of the housing 35, where they mesh with racks formed on two adjacent links of the link mechanism 4. By positioning the spur gears 40a and 40b in this way, and by meshing with the two adjacent links of the link mechanism 4, bending forces on these two links are suppressed, and bending is prevented. In other words, the spur gears 40a and 40b function as a restraining mechanism provided at the exit portion of the housing 35 that prevents bending of at least two links. As a result, as shown in Figure 9, the linearly extended links maintain their rigidity without bending or flexing.

[0056] The winding and extending of the links in the link mechanism 4 may be directly driven by the rotation of the spur gears 40a and 40b. Alternatively, a separate drive mechanism may be provided for the winding and extending of the links in the link mechanism 4. In this case, the spur gears 40a and 40b may function solely as a bending prevention mechanism.

[0057] According to this embodiment, the rigidity of the linearly extended link can be maintained.

[0058] (Example 2) Figures 10 to 14 will be used to describe another embodiment of the link system 202 according to the third embodiment. Figure 10 is a perspective side view of the link system 202. Figure 11 is a side view of the link system 202. Figure 12 is a perspective view of the link system 202. Figure 13 is a front view of the link system 202. Figure 14 is a side view showing the state when the links of the link system 202 are extended.

[0059] The link system 202 comprises a link mechanism 5, a storage section 36 for storing the wound-up link, and a screw nut 50.

[0060] The link mechanism 5 is as described in the above-described embodiment. However, each link of the link mechanism 5 has a screw thread formed around it that engages with the screw nut 50.

[0061] The screw nuts 50 are positioned near the exit of the housing 36, where they engage with the threads formed on two adjacent links of the link mechanism 5. By positioning the screw nuts 50 in this way and engaging with the two adjacent links of the link mechanism 5, bending forces on these two links are suppressed, and bending is prevented. In other words, the screw nuts 50 function as a restraining mechanism that prevents bending of at least two links, provided at the exit portion of the housing 36. As a result, as shown in Figure 14, the linearly extended links maintain their rigidity without bending or flexing.

[0062] Furthermore, the winding and unwinding of the links of the link mechanism 4 may be driven by rotating the screw nut 50. In this case, the screw nut 50 combines the functions of both a drive mechanism for winding and unwinding the links of the link mechanism 5 and a restraining mechanism for preventing bending.

[0063] According to this embodiment, the rigidity of the linearly extended link can be maintained.

[0064] [Fourth Embodiment] Figure 15 schematically shows a link 6 used in a link system according to the fourth embodiment. In this embodiment, the link 6 is wound in a spiral shape. In this case, the dimensions of each link and each connecting rod may be configured such that the radius from the base of the wound link increases continuously or discontinuously towards the tip.

[0065] According to this embodiment, the extension ratio of the link system can be further improved.

[0066] [Fifth Embodiment] A linear actuator 300 according to the fifth embodiment will be described using Figures 16 to 19. Figure 16 is a perspective side view of the linear actuator 300. Figure 17 is a perspective view of the linear actuator 300. Figure 18 is a front view of the linear actuator 300. Figure 19 is a side view showing the state when the link of the linear actuator 300 is extended.

[0067] The linear actuator 300 comprises a link mechanism 7, a storage section 37 for housing the wound-up link, a motor 60, a worm gear 61, and a worm wheel 62.

[0068] The link mechanism 7 is the one described in the above-mentioned embodiment.

[0069] When the motor 60 rotates, its rotational force is transmitted to the link mechanism 7 via the worm gear 61 and worm wheel 62, causing the link to be wound up or extended. In other words, the linear actuator 300 of this embodiment comprises a link mechanism 7 and a power mechanism for winding up and extending the link.

[0070] Therefore, according to this embodiment, it is possible to provide a compact linear actuator with a high extension ratio, multi-point stopping capability, and small installation space.

[0071] [Sixth Embodiment] The aforementioned linkage mechanisms, linkage systems, or linear actuators can be applied to body support devices that assist the user's physical movements. These body support devices include those that assist the joint movements of the upper limbs, such as the fingers, elbows, and shoulders, and those that assist the movements of the lower limbs, such as the knees and hips. The linkage mechanisms, linkage systems, and linear actuators according to the aforementioned embodiments are suitable for such body support devices because they have a high extension ratio, allow for multi-point stopping, and require little installation space.

[0072] Figure 20 schematically shows the process of a user 500 wearing the physical support device 400 according to this embodiment, from a seated position to standing up. Figure 20(a) shows the user 500 in a seated position, Figure 20(b) shows a crouched position, and Figure 20(c) shows the user standing up.

[0073] The physical support device 400 is equipped with a link mechanism according to the embodiment described above. Furthermore, when the link is wound up or extended, the wound-up portion of the link moves in translation while in contact with the floor surface.

[0074] The operation of the physical support device 400 from the time a seated user 500 stands up will be explained below with reference to Figure 20. As shown in Figure 20(a), the link of the physical support device 400 is in its most retracted state when the user 500 is seated. As the user stands up from this position, the link of the physical support device 400 gradually extends (Figure 20(b)). This extension of the link assists the user's standing movement. When the user 500 is fully standing, the link of the physical support device 400 is in its most extended state (Figure 20(c)). With the link extended in this way, the user 500 is supported by the physical support device 400, which helps the user 500 maintain a standing posture.

[0075] As can be easily understood, the physical support device 400 can also assist a standing user 500 in moving from a standing position to a seated position by following the reverse process described above.

[0076] As shown by the rightward arrow in Figure 20, when the link of the body support device 400 is extended, the retracted portion of the link moves to the right while in contact with the floor surface. This translational movement is synchronized with the movement of the upper body to the right when the user 500 stands up.

[0077] In this way, when the link is extended, the retracted portion of the link moves in translation while in contact with the floor surface, which can support the user's movement more efficiently and smoothly.

[0078] Figure 21 is a side view showing a user 500 wearing the physical support device 400 in a seated position. Figure 22 is a side view showing a user 500 wearing the physical support device 400 in a standing position. As shown in the figures, the physical support device 400 in this example includes a lumbar support device 70 and a shoulder support device 71. These support devices allow the user 500 to wear the physical support device 400 stably.

[0079] Figure 23 is a side view of the body support device 401. Figure 24 is a front view of the body support device 401. The body support device 401 comprises 14 links, namely the first link 411, ..., the 14th link 414a. The body support device 401 further comprises 12 connecting rods, namely the first connecting rod 421, ..., the 12th connecting rod 422a. However, in Figures 23 and 24, the reference numerals for the second link to the 13th link and the second connecting rod to the 11th connecting rod are omitted.

[0080] The body support device 401 further comprises two retraction traction cords 431 and two extension traction cords. The retraction traction cords 431 are fixed to one side of the first link 411 (the side on which pulling the retraction traction cords 431 generates a force that retracts each link of the body support device 401). The retraction traction cords 431 extend across from the second link 412 to the 14th link 414a. The extension traction cords 432 are fixed to the other side of the first link 411 (the side on which pulling the extension traction cords 432 generates a force that extends each link of the body support device 401). The extension traction cords 432 extend across from the second link 412 to the 14th link 414a (the side opposite to the retraction traction cords 431). By providing the retraction traction cord 431 and extension traction cord 432 in this manner, each link of the body support device 401 can be retracted by pulling the retraction traction cord 431, and each link of the body support device 401 can be extended by pulling the extension traction cord 432.

[0081] Figure 25 is a side view of the link mechanism of the body support device 401 when it is fully retracted. Figure 26 is a front view of the link mechanism of the body support device 401 when it is fully retracted. Each link of the body support device 401 is configured to be U-shaped when viewed from the front. Furthermore, the dimensions of each link and connecting rod of the body support device 401 are configured such that the radius from the base of the retracted link increases continuously towards the tip. By designing each link and connecting rod of the body support device 401 in this way, the retracted portion of the link can be stored in a spiral shape. Furthermore, because the U-shaped portion of each link contacts the floor surface, when the links of the body support device 401 are retracted or extended, the retracted portion of the link can move in translation while in contact with the floor surface.

[0082] Figure 27 is a photograph taken from the front when user 500 is wearing the physical support device 401 on the left side of his body. Figure 28 is a photograph taken from the left side when user 500 is wearing the physical support device 401 on the left side of his body.

[0083] Figure 29 is a side view photograph of two prototypes of the body support device according to the sixth embodiment, namely the first prototype 402 and the second prototype 403. Figure 30 is a front view photograph of the first prototype 402 and the second prototype 403.

[0084] The second prototype 403 includes a linkage mechanism, a winding traction cord 431, and an extension traction cord 432, as well as a motor 440 for pulling the winding traction cord 431 and the extension traction cord 432. This allows for more efficient assistance of the user's movement.

[0085] Figure 31 schematically shows how the body support device according to the sixth embodiment assists the user from sitting to standing and from standing to walking.

[0086] The user wears the physical support device on both sides of their body. As mentioned earlier, the links of the physical support device are most retracted when the user is seated. As the user stands up, the links of the physical support device gradually extend. This extension of the links assists the user in standing up. When the user is fully standing, the links of the physical support device are in their most extended state. In this extended state, the user is supported by the physical support device, which helps the user maintain an upright posture.

[0087] Furthermore, when the user transitions from a standing position to walking, the link of the body support device on the side of the leg that the user lifts during walking is retracted. This retracting motion of the link assists the user in lifting their leg. Subsequently, when the user extends the leg that they lifted, the link of the body support device on the side of the leg being extended is extended. This extending motion of the link assists the user in extending their leg. Similarly, by repeatedly retracting and extending the links of the body support devices alternately on the left and right sides, the user's walking can be assisted.

[0088] [Each aspect of this disclosure] A link mechanism in one aspect of the present disclosure is a retractable and extendable link mechanism comprising at least four links rotatably connected in series with respect to each other, and at least two connecting rods connecting the links alternately. The connecting rods rotatably connect the links to be connected by diagonally crossing the links between them. The connecting rods are arranged substantially parallel to each other when the links are extended in a straight line.

[0089] According to this embodiment, a compact link mechanism can be provided that has a high extension ratio, enables multi-point stopping, and requires minimal installation space.

[0090] A link system in one aspect of the present disclosure comprises a link mechanism as described above and a storage section for storing a wound-up link.

[0091] According to this embodiment, a compact link system can be provided that has a high extension ratio, allows for multi-point stopping, and requires minimal installation space, and can accommodate the retracted link.

[0092] In one embodiment, the exit portion of the storage section is provided with a restraining mechanism that prevents bending of at least two links.

[0093] According to this embodiment, the rigidity of the linearly extended link can be maintained.

[0094] In one embodiment, the link is wound in a spiral shape.

[0095] According to this embodiment, the extension ratio of the link system can be further improved.

[0096] A linear actuator in one aspect of the present disclosure comprises a link mechanism as described above and a power mechanism for winding and extending the link.

[0097] According to this embodiment, a compact linear actuator can be provided that has a high extension ratio, is capable of multi-point stopping, and requires little installation space.

[0098] A physical assistance device in one aspect of the present disclosure comprises a link mechanism in any of the above-described aspects.

[0099] According to this embodiment, it is possible to provide a compact body support device that has a high extension ratio, is capable of multi-point stopping, and requires little installation space.

[0100] In one embodiment, when the link is wound up or unwound, the wound-up portion of the link moves in translational motion while in contact with the floor surface.

[0101] According to this embodiment, the user's movements can be supported more efficiently.

[0102] The present disclosure has been described above based on examples. These examples are illustrative, and it will be understood by those skilled in the art that various modifications are possible for each component and each combination of processing processes, and that such modifications are also within the scope of the present disclosure.

[0103] For example, the linear actuator 300 of the fifth embodiment uses a motor 60, a worm gear 61, and a worm wheel 62 as a power mechanism for winding and extending the link. However, it is not limited to this, and the transmission mechanism that transmits the rotational force of the motor may be a spur gear, a helical gear, a bevel gear, etc. Furthermore, the power source is not limited to a motor, but may be hydraulic or pneumatic, or even artificial muscle.

[0104] This modified example allows for increased flexibility in configuration.

[0105] The embodiments and modifications have been described above. In understanding the technical concept abstracted from the embodiments and modifications, that technical concept should not be interpreted restrictively to the content of the embodiments and modifications. The embodiments and modifications described above are merely examples, and many design changes, such as changes, additions, and deletions of components, are possible. In the embodiments, the content in which such design changes are possible is emphasized with the notation "embodiment." However, design changes are also permitted in content without such notation. [Industrial applicability]

[0106] The link mechanism and link system of the present invention can be used in structures such as flexible troughs and as components of linear actuators. The linear actuator of the present invention can be used in robotics, automation, and industrial applications. The body assist device of the present invention can be used to assist joint movements of the upper limbs such as fingers, elbows, and shoulders, and to assist movements of the lower limbs such as knees and hips. [Explanation of symbols]

[0107] 1. Link mechanism, 2. Link mechanism, 3. Link mechanism, 4. Link mechanism, 5. Link mechanism, 6 links, 7. Link mechanism, 11. The first link, 12. Second link, 13. The third link, 14. The fourth link, 15. The fifth link, 16. The sixth link, 17. The 7th link, 18. The 8th link, 19. The 9th link, 10a ··The 10th link, 11a ··The 11th link, 12a ··The 12th link, 21. First connecting rod, 22. Second connecting rod, 23. The third connecting rod, 24. The fourth connecting rod, 25. The fifth connecting rod, 26. The sixth connecting rod, 27. The 7th connecting rod, 28. The 8th connecting rod, 29. The 9th connecting rod, 20a ··The 10th connecting rod, 30. Storage compartment, 31 rotors, 32. End pin, 33 guide slots, 34 guide slots, 35. Storage compartment, 36. Storage compartment, 37. Storage compartment, 40a spur gear, 40b...spur gear, 50. Screw nuts, 60 motor, 61. Worm gear, 62 worm wheel, 70...lumbar fixation device, 71...Shoulder fixation device, 101. Through hole, 102. Through hole, 103. Through hole, 104. Through hole, 105...Through hole, 106...Through hole, 107. Through hole, 200 Link System, 201 Link System, 202 Link System, 300 linear actuators, 400...Physical support equipment, 401...Physical support equipment, 402...First prototype, 403...Second prototype, 411...First link, 412...Second link, 414a ··The 14th link, 421 ··First connecting rod, 422a ··The 12th connecting rod, 431. Retractable towing rope, 432...Tow string for extension, 440 motor, 500 users.

Claims

1. A link mechanism that can be retracted and extended, At least four links connected in series so as to be rotatable to one another, It comprises at least two connecting rods that connect the aforementioned links alternately, The connecting rod diagonally crosses the links between the links to be connected, rotatably connecting the links to be connected. The link mechanism is characterized in that the connecting rods are arranged substantially parallel to each other when the link is extended in a straight line.

2. The link mechanism described in claim 1, A link system characterized by comprising a storage section for storing the wound-up links.

3. The link system according to claim 2, characterized in that the outlet portion of the storage section is provided with a restraining mechanism that prevents bending of at least two links.

4. The link system according to claim 2 or 3, characterized in that the link is wound in a spiral shape.

5. The link mechanism described in claim 1, A linear actuator comprising a power mechanism for winding and extending the aforementioned link.

6. A body support device characterized by comprising the link mechanism described in claim 1 or 2.

7. The body support device according to claim 6, characterized in that when the link is wound up or extended, the wound-up portion of the link moves in translational motion while in contact with the floor surface.

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