Walking mechanism

Abstract

The walking mechanism comprises a torso and a first and second mechanism connected by a crankshaft. Each of the first and second mechanisms includes a crank arm rotatable integrally with the crankshaft, a first link rotatably connected to the crank arm about a first connection point, and a second link rotatably connected to the first link about a second connection point and rotatably connected to the torso about a third connection point. The crank arm of each mechanism is 180 degrees out of phase with respect to the crankshaft. The second connection point of each mechanism is located on the same side with respect to the straight line connecting the crankshaft and the third connection point. Each first link of each mechanism has a main part connecting the crank arm and the second link, and a leg part extending in a predetermined direction from a predetermined position of the main part and making contact with the walking surface. In each mechanism, a single first link transmits the force received by the leg part from the walking surface to the crank arm at the first connection point, with its movement restricted by the second link at the second connection point.

Description

[Technical Field]

[0001] The present disclosure relates to a walking mechanism. [Background Art]

[0002] Walking mechanisms have been conventionally known (see, for example, Patent Document 1). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2021-166588 [Patent Document 2] International Publication No. 2017 / 212899 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The walking devices disclosed in Patent Documents 1 and 2 mentioned above have a problem, for example, that the configuration is complicated.

[0005] Accordingly, an object of the present disclosure is to solve the problem described above and provide a walking mechanism with a simple configuration. [Means for Solving the Problem]

[0006] To achieve the above object, the walking mechanism according to the present disclosure can employ, for example, configurations as described in (1) to (17) below.

[0007] (Configuration 1) An example configuration of the walking mechanism of the present disclosure includes: a body; a first mechanism disposed on one side of the body; a second mechanism disposed on the other side of the body; and a crank shaft connecting the first mechanism and the second mechanism, wherein each of the first mechanism and the second mechanism is A crank arm connected to the crankshaft and rotatable integrally with the crankshaft, A first link is rotatably connected to the crank arm around a first connection point, The device comprises a first link rotatably connected to the first link about a second connection point, and a second link rotatably connected to the body about a third connection point, The crank arm of the first mechanism and the crank arm of the second mechanism are in phase with respect to the crank shaft, The second connection point of the first mechanism and the second connection point of the second mechanism are located on the same side with respect to the straight line connecting the crankshaft and the third connection point. Each of the first and second mechanisms satisfies the following conditions (1) and (2): L1+L2≧D+CL...Formula (1) |L1-L2|≦|D-CL|···Equation (2) [L1 is the effective length of the first link, which is the distance between the first connection point and the second connection point; L2 is the effective length of the second link, which is the distance between the third connection point and the second connection point; D is the distance between the crankshaft and the third connection point; and CL is the effective length of the crank arm, which is the distance between the crankshaft and the first connection point.] The first link of the first mechanism and the second mechanism each have a main part that connects the crank arm and the second link, and a leg that extends in a predetermined direction from a predetermined position of the main part and makes contact with the walking surface. In each of the first and second mechanisms, a single first link transmits to the crank arm at the first connection point the force received by the leg from the walking surface, with its movement restricted by the second link at the second connection point.

[0008] According to configuration 1, the crank arm can be rotated simply and effectively by a single first link, which has legs that make contact with the walking surface and receive forces from the walking surface, while its movement is restricted by a second link.

[0009] (Configuration 2) In configuration 1, The leg portion of the first mechanism is configured to make contact with the walking surface after the state in the first mechanism has passed where the first connection point, the crankshaft, and the second connection point are aligned in that order in a straight line, and the leg portion of the second mechanism is configured to make contact with the walking surface after the state in the second mechanism has passed where the first connection point, the crankshaft, and the second connection point are aligned in that order in a straight line.

[0010] According to configuration 2, when a force is received from the walking surface after contact with the ground, the first connection point can smoothly rotate the crankshaft in the same direction.

[0011] (Composition 3) In configuration 1 or configuration 2, The legs of the first mechanism may be configured to make contact with the ground before the crankshaft, the first connection point, and the second connection point reach a state in which they are aligned in that order in the second mechanism, and the legs of the second mechanism may be configured to make contact with the ground before the crankshaft, the first connection point, and the second connection point reach a state in which they are aligned in that order in the first mechanism.

[0012] According to configuration 3, even if the other mechanism receives force from the walking surface on its leg, before it becomes unable to rotate the crankshaft, one leg will be in contact with the walking surface and able to receive force from it, thus allowing the crankshaft to rotate continuously.

[0013] (Composition 4) In any one of the configurations from Configuration 1 to Configuration 3, In the first mechanism, the leg portion of the first mechanism is configured to leave the walking surface before reaching a state where the crankshaft, the first connection point, and the second connection point are aligned on a straight line in this order, and in the second mechanism, the leg portion of the second mechanism may be configured to leave the walking surface before reaching a state where the crankshaft, the first connection point, and the second connection point are aligned on a straight line in this order.

[0014] According to Configuration 4, it is possible to avoid receiving unnecessary force from the walking surface.

[0015] (Configuration 5) In any one of Configurations 1 to 4, In the second mechanism, the leg portion of the first mechanism is configured to leave the walking surface after passing a state where the first connection point, the crankshaft, and the second connection point are aligned on a straight line in this order, and in the first mechanism, the leg portion of the second mechanism may be configured to leave the walking surface after passing a state where the first connection point, the crankshaft, and the second connection point are aligned on a straight line in this order.

[0016] According to Configuration 5, rotation of the crankshaft can be performed by one leg portion until the crankshaft is brought into a rotating state by the other leg portion.

[0017] (Configuration 6) In any one of Configurations 1 to 5, For each of the first mechanism and the second mechanism, when the leg portion receives a force from the walking surface, the configuration may be such that a rotation direction of the second connection point about the third connection point with respect to the first link associated with the leg portion receiving the force matches the rotation direction of the crankshaft.

[0018] According to Configuration 6, in the mechanism on the side to which force is applied, the movement trajectory of the second connection point can be made similar to the movement trajectory of the first connection point that rotates the crankshaft, so the applied force can be naturally used for rotation of the crankshaft.

[0019] (Composition 7) In any one of the configurations from configuration 1 to configuration 6, With respect to each of the first and second mechanisms, when the second connection point of one mechanism is furthest from the crankshaft, the second connection point of the other mechanism may be configured such that it is on the opposite side of the line passing through the first connection point and the crankshaft from the third connection point.

[0020] (Composition 8) In any one of the configurations from Configuration 1 to Configuration 7, For each of the first and second mechanisms, the position of the second connection point when it is closest to the crankshaft may be configured to be on the opposite side from the third connection point with respect to a straight line passing through the position of the second connection point when it is furthest from the crankshaft and the crankshaft.

[0021] According to configurations 7 and 8, the rotational direction of the second connection point on the force-applied side can be made to coincide with the rotational direction of the crankshaft.

[0022] (Composition 9) In any one of the configurations from configuration 1 to configuration 8, For each of the first and second mechanisms, the effective length of the second link, which is the distance between the second connection point and the third connection point, may be longer than the distance between the crankshaft and the third connection point.

[0023] According to configuration 9, the rotational direction of the second connection point on the side where the force is applied can be made to coincide with the rotational direction of the crankshaft.

[0024] (Composition 10) In any one of the configurations from configuration 1 to configuration 9, For each of the first and second mechanisms, the member that transmits force from the walking surface and is rotatably connected to the crank arm may be a single first link.

[0025] According to configuration 10, since the only component that rotates the crank arm is the first link, the mechanism for rotating the crank arm can be simplified.

[0026] (Composition 11) In any one of the configurations from configuration 1 to configuration 10, In each of the first and second mechanisms, the crank arm and the first link may be connected only at the first connection point, whether directly or indirectly.

[0027] According to configuration 11, the movement of the first link and the movement of the crank arm can be simply synchronized.

[0028] (Composition 12) In any one of the configurations from configuration 1 to configuration 11, With respect to each of the first and second mechanisms, the first link and the second link may be connected only at the second connection point, whether directly or indirectly.

[0029] (Composition 13) In any one of the configurations from configuration 1 to configuration 12, In each of the first and second mechanisms, there may be no members other than the first and second links that move in conjunction with the rotation of the crankshaft.

[0030] (Composition 14) In any one of the configurations from configuration 1 to configuration 13, Each of the first and second mechanisms may consist only of the crank arm, a single first link, and a single second link.

[0031] According to configuration 14, a walking mechanism can be realized with a simple configuration.

[0032] (Composition 15) In any one of the configurations from configuration 1 to configuration 14, The crank arm of the first mechanism and the crank arm of the second mechanism may be linear members extending in directions 180 degrees different from the crank shaft.

[0033] According to configuration 15, the structure of the walking mechanism can be simplified.

[0034] (Composition 16) In any one of the configurations from configuration 1 to configuration 15, Each of the first and second mechanisms satisfies the following conditions (1) and (2): L1 + L2 > D + CL ... Equation (1) |L1-L2|<|D-CL|···Formula (2) [L1 is the effective length of the first link, which is the distance between the first connection point and the second connection point; L2 is the effective length of the second link, which is the distance between the third connection point and the second connection point; D is the distance between the crankshaft and the third connection point; and CL is the effective length of the crank arm, which is the distance between the crankshaft and the first connection point.] Furthermore, for each of the first and second mechanisms, the distance between the crankshaft and the third connection point may be longer than the effective length of the crank arm, which is the distance between the crankshaft and the first connection point.

[0035] According to configuration 16, the second connection point can be prevented from moving across the straight line connecting the crankshaft and the third connection point. [Brief explanation of the drawing]

[0036] [Figure 1] This is a schematic side view showing a crank mechanism according to one embodiment of the present disclosure, in which the second connection point of the first mechanism is located at the far dead center. [Figure 2] Figure 1 is a side view showing the support and the first mechanism of the crank mechanism. [Figure 3] Figure 1 is a side view showing the support and the second mechanism of the crank mechanism. [Figure 4]This is a schematic side view showing a crank mechanism according to one embodiment of the present disclosure, in which the second connection point of the first mechanism is located near dead center. [Figure 5] This is a schematic side view showing a crank mechanism according to one embodiment of the present disclosure, in which the second connection point of the second mechanism is located at the far dead center. [Figure 6] This is a schematic side view showing a crank mechanism according to one embodiment of the present disclosure, in which the second connection point of the second mechanism is located near dead center. [Figure 7] This is a schematic diagram illustrating the relationship between the rotation of the second connection point and the far dead center and near dead center in a crank mechanism according to one embodiment. [Figure 8] This is a schematic diagram illustrating the rotation of the crank arm. [Figure 9] This is a schematic diagram illustrating the rotation of the crank arm in the reverse direction. [Figure 10] This is a schematic side view showing a crank mechanism in which the second connection point of the second mechanism is located near dead center when the second connection point of the first mechanism is located near dead center, for comparison with a crank mechanism according to one embodiment of the present disclosure. [Figure 11] This is a schematic diagram illustrating the rotation of the crank arm in the crank mechanism shown in Figure 10. [Figure 12] This is a schematic side view showing a walking mechanism according to one embodiment of the present disclosure. [Figure 13] This is a schematic side view showing the state following Figure 12 when the walking mechanism according to one embodiment of the present disclosure is made to walk. [Figure 14] This is a schematic side view showing the state following Figure 13 when the walking mechanism according to one embodiment of the present disclosure is made to walk. [Figure 15] This is a schematic side view showing the state following Figure 14 when the walking mechanism according to one embodiment of the present disclosure is made to walk. [Figure 16] This is a schematic side view showing the state following Figure 15 when the walking mechanism according to one embodiment of the present disclosure is made to walk. [Figure 17]This is a schematic side view showing the state following Figure 16 when the walking mechanism according to one embodiment of the present disclosure is made to walk. [Figure 18] This is a schematic side view showing a modified example of a walking mechanism according to one embodiment of the present disclosure. [Figure 19] This is a schematic side view showing a modified example of a walking mechanism according to one embodiment of the present disclosure. [Figure 20] This is a schematic bottom view showing a modified example of a walking mechanism according to one embodiment of the present disclosure. [Figure 21] This is a schematic side view showing a bicycle according to one embodiment of the present disclosure. [Figure 22] This is a schematic side view showing the state following Figure 21 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 23] This is a schematic side view showing the state following Figure 22 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 24] This is a schematic side view showing the state following Figure 23 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 25] This is a schematic side view showing the state following Figure 24 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 26] This is a schematic side view showing the state following Figure 25 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 27] This is a schematic side view showing the state following Figure 26 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 28] This is a schematic side view showing the state following Figure 27 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 29] This is a schematic side view showing the state following Figure 28 when a bicycle according to one embodiment of the present disclosure is being driven. [Figure 30] This is a schematic side view illustrating the walking mechanism. [Figure 31] This is a schematic diagram from Figure 30 with the left mechanism omitted. [Figure 32]This is a schematic side view showing the walking mechanism when the right leg makes contact with the walking surface, with the left leg mechanism omitted. [Figure 33] This is a schematic side view illustrating the walking mechanism and is intended to explain the operation of the walking mechanism. [Figure 34] This is a schematic diagram from Figure 33 with the left mechanism omitted. [Figure 35] This is a schematic side view showing the state following Figure 34. [Figure 36] This is a schematic side view showing the state following Figure 35. [Figure 37] This is a schematic side view showing the state following Figure 36. [Figure 38] This is a schematic side view showing the state following Figure 37. [Figure 39] This is a schematic side view showing the state that follows Figure 38. [Figure 40] This is a schematic side view showing the state following Figure 39. [Figure 41] This is a schematic side view showing the state following Figure 40. [Figure 42] This is a schematic side view showing the state following Figure 41. [Figure 43] This is a schematic side view showing the state that follows Figure 42. [Figure 44] This is a schematic side view showing the state following Figure 43. [Figure 45] This is a schematic side view showing the state following Figure 44. [Modes for carrying out the invention]

[0037] Hereinafter, an embodiment of this disclosure will be described with reference to the drawings. However, this embodiment does not limit the present invention. In the drawings, substantially identical components are denoted by the same reference numerals. The drawings are schematic, and the proportions of the dimensions, etc., do not necessarily correspond to those of reality.

[0038] In the following, for the sake of clarity, terms such as "up," "down," "height," "front," and "back" may be used to indicate directions, assuming a specific state of use in one mode of operation. However, this does not mean to limit the modes of use of the crank mechanism and walking mechanism described herein. In the following description, each direction (up / down, front / back, left / right) refers to the direction perpendicular to the walking surface 100 and the direction in which the walking mechanism moves. However, this does not mean to limit the modes of use of the walking mechanism. In this disclosure, "connection" is not limited to direct connection between members, but also includes, for example, cases where two members are both connected to a common joint or axis.

[0039] (Configuration of the crank mechanism) The configuration of the crank mechanism 1 according to one embodiment of this disclosure will be described below. In this disclosure, when "crank mechanism," "support," "crank shaft," "crank arm," "first link," "second link," "first connection point," "second connection point," and "third connection point" are referred to as the crank mechanism, etc., as one embodiment.

[0040] Figure 1 is a schematic side view showing a crank mechanism 1 according to one embodiment of the present disclosure. Figure 2 is a side view showing the support 2 and the first mechanism 3 of the crank mechanism 1 shown in Figure 1. Figure 3 is a side view showing the support 2 and the second mechanism 4 of the crank mechanism 1 shown in Figure 1.

[0041] In this specification and in each figure, for the sake of explanation, the direction perpendicular to the support 2 is defined as the X-axis direction, the direction in which the crankshaft 22 extends is defined as the Y-axis direction, and the direction in which the support 2 extends is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are intersecting directions (orthogonal directions in each embodiment).

[0042] In this specification and in each figure, for the sake of explanation, the positive direction of the X-axis (the direction indicated by the X-axis arrow in the figure) is referred to as the front, and the negative direction of the X-axis (the direction opposite to the direction indicated by the X-axis arrow in the figure) is referred to as the back. The same applies to the Y-axis and Z-axis.

[0043] The crank mechanism 1 can be applied not only to walking mechanisms, but also to toys, models, mechanisms attached to humans or animals, bicycles, generators, robots used for various industrial purposes, etc. Of course, the applications of the crank mechanism 1 are not limited to these.

[0044] As shown in Figures 1, 2, and 3, the crank mechanism 1 comprises a support 2, a first mechanism 3, and a second mechanism 4. The support 2 is a member that supports the first mechanism 3 and the second mechanism 4. The first mechanism 3 is a mechanism positioned in front of the support 2 on the paper, and the second mechanism 4 is a mechanism positioned behind the support 2 on the paper. That is, the first mechanism 3 and the second mechanism 4 are positioned on both sides of the support 2. The first mechanism 3 and the second mechanism 4 may be positioned on the surface of the side of the support 2, or they may be positioned embedded in the side of the support 2. The materials of the support 2, the first mechanism 3, and the second mechanism 4 are arbitrary and consist of, for example, resin, metal, and wood.

[0045] The support 2 consists of a main body 21 on which a crankshaft 22 is positioned. In this embodiment, the main body 21 is rod-shaped and extends along the Z-axis. However, the shape of the main body 21 is not limited to a rod shape; it may be any shape, such as the shape of a human or animal's torso, or the frame of a bicycle.

[0046] The crankshaft 22 extends in the Y-axis direction. For example, the crankshaft 22 is inserted into a through-hole that penetrates the main body 21 in the Y-axis direction. For example, the length of the crankshaft 22 in the Y-axis direction is longer than the length of the through-hole in the main body 21 in the Y-axis direction. As a result, both ends of the crankshaft 22 in the Y-axis direction protrude from the main body 21. The crankshaft 22 is rotatable about the Y-axis direction. Note that the configuration in which the crankshaft 22 is rotatable about the Y-axis direction is not limited to the configuration described above, and any configuration may be adopted as appropriate.

[0047] The first mechanism 3 is rotatably connected to one side of the support 2. The second mechanism 4 is rotatably connected to the other side of the support 2.

[0048] The first mechanism 3 includes a crank arm 30 extending from one end of the crankshaft 22 in a direction perpendicular to the Y-axis direction. The second mechanism 4 includes a crank arm 40 extending from the other end of the crankshaft 22 in a direction perpendicular to the Y-axis direction.

[0049] The crank arms 30 and 40 are connected to the crankshaft 22. Crank arm 30 is fixed to one end of the crankshaft 22. Crank arm 40 is fixed to the other end of the crankshaft 22. The crank arms 30 and 40 rotate together as the crankshaft 22 rotates around the crankshaft 22. In the following, when it is not necessary to distinguish between crank arm 30 and crank arm 40, they may be collectively referred to as "crank arms".

[0050] In this embodiment, the crank arms 30 and 40 are linear in shape (in other words, rod-shaped). In this embodiment, the crank arms 30 and 40 extend in directions 180 degrees apart from the crankshaft 22.

[0051] The crank arm may have any shape, not limited to a rod shape, as long as it can connect to the first link at a point displaced from the crankshaft 22. For example, the crank arm may be wide, its end does not need to be straight, and it may also be shaped like a circle or a disc (or a semi-disc, etc.) centered on the crankshaft 22, with the first link connected to the end of the disc. Furthermore, the crank arm 30 and the crank arm 40 may have different shapes.

[0052] The first mechanism 3 includes a crank arm 30, a first link 34, and a second link 35. The crank arm 30 and the first link 34 are rotatably connected to each other at a first connection point 31. The first link 34 and the second link 35 are rotatably connected to each other at a second connection point 32. The second link 35 is rotatably connected to the support 2 at a third connection point 33.

[0053] The second mechanism 4 includes a crank arm 40, a first link 44, and a second link 45. The crank arm 40 and the first link 44 are rotatably connected to each other at a first connection point 41. The first link 44 and the second link 45 are rotatably connected to each other at a second connection point 42. The second link 45 is rotatably connected to the support 2 at a third connection point 43. In the following, when it is not necessary to distinguish between the first link 34 and the first link 44, they may be collectively referred to as the "first link." Similarly, when it is not necessary to distinguish between the second link 35 and the second link 45, they may be collectively referred to as the "second link." Similarly, when it is not necessary to distinguish between the first connection point 31 and the first connection point 41, they may be collectively referred to as the "first connection point." Similarly, when it is not necessary to distinguish between the second connection point 32 and the second connection point 42, they may be collectively referred to as the "second connection point." Furthermore, when there is no need to distinguish between the third connection point 33 and the third connection point 43, they are sometimes collectively referred to as the "third connection point."

[0054] In this embodiment, the first and second links are straight, but they can be any shape, such as a bent shape or a curved shape.

[0055] In this embodiment, the first mechanism 3 consists only of a crank arm 30, a first link 34, and a second link 35, and the second mechanism 4 consists only of a crank arm 40, a first link 44, and a second link 45.

[0056] The configurations of the first connection point 31, second connection point 32, third connection point 33, first link 34, and second link 35 of the first mechanism 3 will be described below. The configurations of the first connection point 41, second connection point 42, third connection point 43, first link 44, and second link 45 of the second mechanism 4 are the same as the corresponding elements of the first mechanism 3, so their description will be omitted and explained as needed.

[0057] The first connection point 31 is the connection point between the crank arm 30 and the first link 34. When viewed along the Y-axis, the first connection point 31 is located at a different position from the crankshaft 22 (a position displaced from the crankshaft 22). In other words, the first connection point 31 is located away from the crankshaft 22 and is typically located at the end of the crank arm 30. However, the first connection point 31 may be located in a place other than the end, such as in the middle of the crank arm 30. The first link 34 is rotatable around the Y-axis at the first connection point 31 relative to the crank arm 30.

[0058] For example, holes may be provided in the crank arm 30 and the first link 34 at positions corresponding to the first connection point 31, and a joint may be inserted into the hole in the crank arm 30 and the hole in the first link 34 to connect the first link 34 and the crank arm 30 so as to be rotatable around the Y-axis direction. Note that the configuration in which the first link 34 is connected to the crank arm 30 so as to be rotatable around the Y-axis direction is not limited to the above configuration, and any configuration may be adopted as appropriate.

[0059] The first link 34 and the second link 35 are connected at the second connection point 32 so as to be rotatable relative to each other about the Y-axis direction. The second connection point 32 is located at a different position on the first link 34 than the first connection point 31, and is typically located at the end of the first link 34 opposite to the end where the first connection point 31 is located. However, the second connection point 32 may also be located in the central part of the first link 34, for example.

[0060] In this embodiment, the configuration in which the first link 34 and the second link 35 are rotatably connected to each other at the second connection point 32 may be the same as the configuration described above in which the first link 34 and the crank arm 30 are rotatably connected at the first connection point 31, but is not limited to this, and any configuration may be adopted as appropriate.

[0061] The second link 35 is rotatably connected to the main body 21 of the support 2 at the third connection point 33, with respect to the Y-axis direction. When viewed along the Y-axis direction, the third connection point 33 is located at a different position from where the crankshaft 22 is positioned. In other words, the third connection point 33 is located at a distance from the crankshaft 22 on the support 2.

[0062] In this embodiment, the configuration in which the second link 35 is rotatably connected to the main body 21 at the third connection point 33 may be the same as the configuration in which the first link 34 is rotatably connected to the crank arm 30 as described above, but is not limited to this, and any configuration may be adopted as appropriate.

[0063] Each of the crank arms 30 and 40 is fixed to the crankshaft 22 such that they are 180 degrees out of phase with respect to each other. Therefore, when viewed along the Y-axis, the first connection point 31 is in a different position from the first connection point 41. In this embodiment, when viewed along the Y-axis, the first connection point 31 and the first connection point 41 are point-symmetric with respect to the axis of the crankshaft 22. When the crankshaft 22 rotates, the crank arms 30 and 40 rotate while maintaining their 180-degree phase difference.

[0064] As shown in Figure 1, in this embodiment, the length CL from the axis center of the crankshaft 22 to the first connection point 31 in the crank arm 30 is the same as the effective crank arm length CL of the crank arm 40. The length from the axis center of the crankshaft 22 to the first connection point in the crank arm is called the effective crank arm length CL. Note that the effective crank arm length CL of the crank arm 30 may be different from the effective crank arm length CL of the crank arm 40.

[0065] In this embodiment, the effective length L1 of the first link 34 is the same as the effective length L1 of the first link 44. The effective length L1 of the first link is the length of the line segment connecting the first connection point and the second connection point in the first link. However, the effective length L1 of the first link 34 may be different from the effective length L1 of the first link 44.

[0066] In this embodiment, the effective length L2 of the second link 35 is the same as the effective length L2 of the second link 45. The effective length L2 of the second link is the length of the line segment connecting the second connection point and the third connection point in the second link. Note that the effective length L2 of the second link 35 may be different from the effective length L2 of the second link 45.

[0067] In this embodiment, when viewed along the Y-axis, the positions of the third connection point 33 and the third connection point 43 are the same. However, when viewed along the Y-axis, the positions of the third connection point 33 and the third connection point 43 may be different.

[0068] When viewed along the Y-axis, the second connection point 32 and the second connection point 42 are configured to be on the same side with respect to the straight line SL2 (also called baseline SL2) passing through the crankshaft 22 and the third connection points 33 and 43. In this embodiment, when viewed along the Y-axis, both the second connection point 32 and the second connection point 42 are located behind the baseline SL2 (in the negative direction of the X-axis). Also, the second link 35 and the second link 45 are configured to be on the same side with respect to baseline SL2.

[0069] In this embodiment, when viewed along the Y-axis, the effective length L2 of the second link 35 and the effective length L2 of the second link 45 are each longer than the distance D (also called the base distance D) from the axis center of the crankshaft 22 to the third connection points 33 and 43.

[0070] In this embodiment, the only component connected to the crank arm 30, aside from the crankshaft 22, is the first link 34. In other words, no components other than the first link 34 are connected to the crank arm 30. The only component connected to the crank arm 40, aside from the crankshaft 22, is the first link 44. In other words, no components other than the first link 44 are connected to the crank arm 40.

[0071] In this embodiment, the crank arm 30 and the first link 34 are connected only at the first connection point 31, regardless of whether the connection is direct or indirect (connection via another member in between), and the crank arm 40 and the first link 44 are connected only at the first connection point 41, regardless of whether the connection is direct or indirect. In this embodiment, the first link 34 and the second link 35 are connected only at the second connection point 32, regardless of whether the connection is direct or indirect, and the first link 44 and the second link 45 are connected only at the second connection point 42, regardless of whether the connection is direct or indirect.

[0072] In this embodiment, for the first mechanism 3, the only components that operate in conjunction with the rotation of the crankshaft 22 are the first link 34 and the second link 35. For the second mechanism 4, the only components that operate in conjunction with the rotation of the crankshaft 22 are the first link 44 and the second link 45. Note that the first mechanism 3 and the second mechanism 4 may also include components that do not operate in conjunction with the rotation of the crankshaft 22. For example, a component such as a bicycle pedal that rotates around the second connection point may be attached at the second connection point. Here, the pedal-like component is a component that can rotate around the second connection point independently of the movement of the crank arm, the first link, and the second link, and does not operate in conjunction with the rotation of the crankshaft 22.

[0073] In this embodiment, the sum of the effective length L1 of the first link 34 and the effective length L2 of the second link 35 is greater than or equal to the sum of the base distance D and the effective length CL of the crank arm 30. Similarly, the sum of the effective length L1 of the first link 44 and the effective length L2 of the second link 45 is greater than or equal to the sum of the base distance D and the effective length CL of the crank arm 40. In other words, the following equation (1) is satisfied in each of the first mechanism 3 and the second mechanism 4.

[0074] L1+L2≧D+CL...Formula (1)

[0075] This allows the crank arm to rotate 360 ​​degrees. Furthermore, if L1+L2 > D+CL, the second connection point cannot be prevented from moving beyond the baseline SL2. Alternatively, a mechanism may be provided to restrict the second connection point from moving beyond the baseline SL2 when L1+L2 = D+CL.

[0076] In this embodiment, the magnitude of the difference between the effective length L1 of the first link 34 and the effective length L2 of the second link 35 is less than or equal to the magnitude of the difference between the base distance D and the effective length CL of the crank arm 30. In other words, the absolute value of the difference between the effective length L1 of the first link 34 and the effective length L2 of the second link 35 is less than or equal to the absolute value of the difference between the base distance D and the effective length CL of the crank arm 30. Similarly, the magnitude of the difference between the effective length L1 of the first link 44 and the effective length L2 of the second link 45 is less than or equal to the magnitude of the difference between the base distance D and the effective length CL of the crank arm 40. In other words, the absolute value of the difference between the effective length L1 of the first link 44 and the effective length L2 of the second link 45 is less than or equal to the absolute value of the difference between the base distance D and the effective length CL of the crank arm 40. That is, in each of the first mechanism 3 and the second mechanism 4, the following equation (2) is satisfied.

[0077] |L1-L2|≦|D-CL|···Equation (2)

[0078] This allows the crank arm to rotate 360 ​​degrees. Furthermore, if |L1-L2|<|D-CL|, the second connection point cannot be prevented from moving beyond the baseline SL2. If |L1-L2|=|D-CL|, a mechanism may be provided to restrict the second connection point from moving beyond the baseline SL2.

[0079] In this embodiment, when viewed along the Y-axis, the base distance D in each of the first mechanism 3 and the second mechanism 4 is longer than the effective crank arm length CL. This prevents the second connection point from moving beyond the baseline SL2.

[0080] Figure 1 shows the first mechanism 3 in a state where the axis of the crankshaft 22, the first connection point 31, and the second connection point 32 are aligned in that order. This state is when the second connection point 32 is furthest from the axis of the crankshaft 22, and is called the state where the second connection point 32 is at the far dead center (FDC). In this state, even if a force is applied to move the second connection point 32 away from the crankshaft 22, the first link 34 and the second link 35 will not move any further. Also, in this state, if a force is applied to move the second connection point 32 closer to the crankshaft 22, the direction of rotation of the crankshaft 22 becomes undefined. Note that the force applied to move the second connection point 32 away from or closer to the crankshaft 22 may be applied to either the first link 34 or the second link 35 (or both).

[0081] When the second connection point 32 of the first mechanism 3 is at the far dead center (FDC), the first connection point 41, the crankshaft 22, and the second connection point 42 of the second mechanism 4 are not in a straight line in that order.

[0082] Figure 4 shows the first mechanism 3 in a state where the first connection point 31, the crankshaft 22, and the second connection point 32 are aligned in that order. This state is when the second connection point 32 is closest to the crankshaft 22, and is called the state where the second connection point 32 is near dead center (NDC). In this state, even if a force is applied to bring the second connection point 32 closer to the crankshaft 22, the first link 34 and the second link 35 will not move any further. Also, in this state, if a force is applied to move the second connection point 32 away from the crankshaft 22, the direction of rotation of the crankshaft 22 becomes undefined.

[0083] Applying a force in the direction that moves the second connection point 32 closer to the crankshaft 22 when it is at the far dead center (FDC), or applying a force in the direction that moves the second connection point 32 away from the crankshaft 22 when it is at the near dead center (NDC), is preferable to avoid because it results in an unpredictable direction of rotation.

[0084] As is clear from Figure 1, in the crank mechanism 1, when the second connection point 32 of one mechanism (first mechanism 3 in Figure 1) is at the far dead center (FDC), the second connection point 42 of the other mechanism (second mechanism 4 in Figure 1) is not at the near dead center (NDC). The second connection points 32 and 42 each swing (rotate) independently around the third connection point due to the action of the second link which rotates around the third connection point, as the crankshaft 22 rotates, and the direction of the second connection point as seen from the crankshaft 22 changes. When the direction of the second connection point as seen from the crankshaft 22 changes, the position of the first connection point shifts when the crankshaft 22, the first connection point, and the second connection point are on a straight line. Therefore, the phase difference between the first connection point when the second connection point is at the far dead center (FDC) and the first connection point when the second connection point is at the near dead center (NDC) becomes less than 180 degrees. Therefore, when the second connection point of one mechanism is at the far dead center (FDC), the second connection point of the other mechanism, which is 180 degrees out of phase with the second connection point of the other mechanism, is not at the near dead center (NDC).

[0085] Thus, the crank mechanism 1 is configured such that when one mechanism is at the far dead center (FDC), the other mechanism is not at the near dead center (NDC), by connecting the crank arm to the support 2 at a position different from the crankshaft 22 via the first and second links. However, even with this configuration, as will be described later using Figure 11, depending on the design values ​​of the effective length of the crank arm, the effective length of the first link, the effective length of the second link, and the base distance, when one is at the far dead center (FDC), the other may be at the near dead center (NDC). Such design values ​​are, so to speak, singularities, and by determining each design value in a way that avoids singularities like those in Figure 11, it is possible to ensure that when one is at the far dead center (FDC), the other is not at the near dead center (NDC).

[0086] For example, if a force is applied to the first or second link of one mechanism in a direction toward the far dead center (FDC) (in other words, in a direction toward away from the crankshaft 22) and the second connection point of one mechanism reaches the far dead center (FDC) and stops moving, the second connection point of the other mechanism will have passed the near dead center (NDC). Therefore, when the second connection point of one mechanism reaches the far dead center (FDC) and stops moving, if the target of the force is changed to the other mechanism and a force is applied to the first or second link of the other mechanism in a direction toward the far dead center (FDC) and the second connection point moves toward the far dead center, the rotation direction of the crankshaft 22 will not become uncertain, and the crankshaft 22 will continue to rotate in the same direction.

[0087] Furthermore, the timing for changing the target to which force is applied does not have to be when the second connection point of one mechanism reaches the far dead center (FRDC). Since the second connection point of the other mechanism has already passed the near dead center (NDC) before the second connection point of the other mechanism reaches the far dead center (FDC), the timing for changing the target to which force is applied can be after the second connection point of the other mechanism has passed the near dead center (NDC). In other words, the timing for switching the target to which force is applied to the other mechanism can be when the second connection point of one mechanism reaches the far dead center, or it can be before the second connection point of one mechanism reaches the far dead center, as long as the second connection point of the other mechanism has passed the near dead center (NDC).

[0088] This is also true when a force is applied to the first or second link of one mechanism in a direction that causes the second connection point of one mechanism to move toward the near-dead point NDC (in other words, in a direction that causes the second connection point of one mechanism to move toward the crankshaft 22). That is, when the second connection point of one mechanism reaches the near-dead point NDC and stops moving, the second connection point of the other mechanism has passed the far-dead point FDC. Therefore, when the second connection point of one mechanism reaches the near-dead point NDC and stops moving, if the target of the force is changed to the other mechanism and a force is applied to the first or second link of the other mechanism in a direction that causes the second connection point to move toward the near-dead point NDC, the rotation direction of the crankshaft 22 will not become uncertain, and the crankshaft 22 will continue to rotate in the same direction. The timing for switching the target of the force may be when the second connection point of one mechanism reaches the near-dead point NDC, or it may be before the second connection point of one mechanism reaches the near-dead point NDC, as long as the second connection point of the other mechanism has passed the far-dead point.

[0089] In the crank mechanism 1, for each of the first mechanism 3 and the second mechanism 4, when the second connection point of one mechanism becomes the far dead center (FDC), the second connection point of the other mechanism is configured to be on the opposite side of the third connection point with respect to the straight line connecting the first connection point and the center of the crankshaft 22.

[0090] Specifically, as shown in Figure 1, when the second connection point 32 of the first mechanism 3 becomes the far dead center (FDC), the second connection point 42 of the second mechanism 4 is on the opposite side of the third connection point 43 with respect to the straight line SL1 connecting the first connection point 41 and the center of the crankshaft 22. Similarly, as shown in Figure 5, when the second connection point 42 becomes the far dead center (FDC), the second connection point 32 is on the opposite side of the third connection point 33 with respect to the straight line SL1 connecting the first connection point 31 and the center of the crankshaft 22. With this configuration, when a force is applied to the second mechanism 4 in the state shown in Figure 1 such that the second connection point 42 moves toward the far dead center FDC, the direction of rotation of the first link 44 (the direction of rotation of the second connection point 42 around the third connection point 43 (direction of reference numeral 51 in Figure 1) and the direction of rotation of the first connection point 41 around the crankshaft 22 (direction of reference numeral 52 in Figure 1)) coincide with the direction of rotation of the crankshaft 22 (direction of reference numeral 53 in Figure 1).

[0091] When the direction in which force is applied coincides with the direction in which the crankshaft 22 rotates, the action of the crank mechanism 1 becomes natural. For example, when the crank mechanism 1 is used in a passive walking mechanism, the rotational movement of the legs can be made to coincide with the movement that the legs receive from the walking surface.

[0092] Furthermore, if configured as described above, in both the first mechanism 3 and the second mechanism 4, the position of the second connection point at near dead center (NDC) is on the opposite side of the line SL1 passing through the position of the second connection point at far dead center (FDC) and the crankshaft 22, from the third connection point. For example, by making the effective length L2 of the second link longer than the base distance D, when the second connection point of one mechanism is furthest from the crankshaft 22, the second connection point of the other mechanism can be configured to be on the opposite side of the line passing through the first connection point and the crankshaft 22, from the third connection point. However, even if the effective length L2 of the second link is the same as or shorter than the base distance D, it is possible to adjust the effective length CL of the crank arm, the effective length L1 of the first link, the effective length L2 of the second link, and the base distance D so that the position of the second connection point at near dead center (NDC) is on the opposite side of the line passing through the line passing through the position of the second connection point at far dead center (FDC) and the crankshaft 22, from the third connection point. For example, by using a schematic diagram like the one shown in Figure 7, it is possible to select the effective length CL of the crank arm, the effective length L1 of the first link, the effective length L2 of the second link, and the base distance D that satisfy this condition.

[0093] As shown in Figure 1, the crank mechanism 1 is configured such that when viewed along the Y-axis, the angle θ1 is greater than the angle θ2 when the second connection point 32 of the first mechanism 3 is at the far dead center FDC. Angle θ1 is the angle between the straight line SL3 passing through the second connection point 42 and the first connection point 41 of the second mechanism 4 and the straight line SL2 (baseline SL2) passing through the third connection point 43 and the crankshaft 22. Angle θ2 is the angle between the straight line SL1 passing through the second connection point 32 and the first connection point 31 of the first mechanism 3 and the straight line SL2 (baseline SL2) passing through the third connection point 33 and the crankshaft 22.

[0094] Similarly, as shown in Figure 5, the crank mechanism 1 is configured such that when viewed along the Y-axis, the angle θ3 is greater than the angle θ4 when the second connection point 42 of the second mechanism 4 is at the far dead center FDC. The angle θ3 is the angle between the straight line SL3 passing through the second connection point 32 and the first connection point 31 of the first mechanism 3 and the straight line SL2 (baseline SL2) passing through the third connection point 33 and the crankshaft 22. The angle θ4 is the angle between the straight line SL1 passing through the second connection point 42 and the first connection point 41 of the second mechanism 4 and the straight line SL2 (baseline SL2) passing through the third connection point 43 and the crankshaft 22.

[0095] With this configuration, when the second connection point moves toward the far dead center (FDC), the rotational direction of the second connection point around the third connection point coincides with the rotational direction of the crankshaft 22.

[0096] (Operation of the crank mechanism) The operation of the crank mechanism 1 will be explained below with reference to Figures 1, 4, 5, and 6. Figure 1 is a schematic side view showing the state in which the second connection point of the first mechanism is at the far dead center in the crank mechanism 1. Figure 4 is a schematic side view showing the state in which the second connection point 32 of the first mechanism 3 is at the near dead center in the crank mechanism 1. Figure 5 is a schematic side view showing the state in which the second connection point 42 of the second mechanism 4 is at the far dead center in the crank mechanism 1. Figure 6 is a schematic side view showing the state in which the second connection point 42 of the second mechanism 4 is at the near dead center in the crank mechanism 1.

[0097] To operate the crank mechanism 1, an external force can be applied to either the first or second link. The crank mechanism 1 can be operated so that the second connection point moves away from the crankshaft 22, or so that the second connection point moves closer to the crankshaft 22.

[0098] First, we will explain the case in which the crank mechanism 1 is operated so that the second connection point moves away from the crankshaft 22. Operating the crank mechanism 1 so that the second connection point moves away from the crankshaft 22 can be achieved, for example, by applying an external force to the first link. Specifically, a force may be applied to the first link 34 of the second mechanism 4 in Figure 1 in the positive Z-axis direction (upwards; the direction indicated by F11) or in the upper left direction of Figure 1 (the direction indicated by F12). Note that the direction in which the force is applied can be any direction as long as it moves the second connection point away from the crankshaft 22. Furthermore, a force may be applied upwards or to the upper left to the second link 45 of the second mechanism 4.

[0099] By alternately applying force to the first mechanism 3 and the second mechanism 4, the crankshaft 22 can be continuously rotated in the same direction. For example, an external force is applied to the first mechanism 3 until its second connection point 32 is at the far dead center (FDC), then the target of the force is switched to the second mechanism 4, and the force is applied to the second mechanism 4 until its second connection point 42 is at the far dead center (FDC). This process is repeated, thereby continuously rotating the crankshaft 22 in the same direction.

[0100] Furthermore, while a force is applied to one mechanism, the other mechanism operates in conjunction via the crankshaft 22. Specifically, while a force is applied to one mechanism in a direction that moves the second connection point away from the crankshaft 22, the other mechanism moves in a direction that moves the second connection point closer to the crankshaft 22. In the other mechanism, after the second connection point crosses the near-dead point (NDC) during its movement, it moves in a direction that moves away from the crankshaft 22.

[0101] This will be explained in detail with reference to Figures 1, 4, 5, and 6. When the crank mechanism 1 is operated so that the second connection point moves away from the crankshaft 22, the state of the crank mechanism 1 transitions in the order of Figures 1, 4, 5, and 6. By applying an external force to the first mechanism 3 (for example, the first link 34 of the first mechanism 3), the second connection point 32 reaches the state where it is at the far dead center FDC (the state in Figure 1). Subsequently, when an external force is applied to the second mechanism 4 (for example, the first link 44 of the second mechanism 4) so ​​that the second connection point 42 moves toward the far dead center FDC, the second connection point 42 rotates around the third connection point 43 in the direction of arrow 51. Since the second connection point 42 has passed the near dead center NDC, it rotates the first connection point 41 in the direction of arrow 52 and rotates the crankshaft 22 in the direction of arrow 53 (i.e., in Figure 1, the crankshaft 22 rotates clockwise). When an external force is continuously applied to the second mechanism 4, the crankshaft 22 continues to rotate and operates until the second connection point 42 reaches the far dead center FDC (the state in Figure 5). In the process, the second connection point 32 of the first mechanism 3 rotates via the rotating crankshaft 22, passing the state where it is located at the near dead center NDC (the state in Figure 4). In other words, while a force is being applied to the second mechanism 4, the second connection point 32 of the first mechanism 3 on the opposite side passes the near dead center NDC.

[0102] After reaching the state shown in Figure 5, the target of the external force is changed to the first mechanism 3. Specifically, when a force is applied to the first mechanism 3 such that the second connection point 32 is directed toward the far dead center FDC, the second connection point 32 rotates around the third connection point 33 in the direction of arrow 54. At this time, since the second connection point 32 has passed the near dead center NDC, the first connection point 31 rotates in the direction of arrow 55 (the same direction as the rotation in the state transition from Figure 1 to Figure 4 and then to Figure 5), causing the crankshaft 22 to rotate in the direction of arrow 56 (i.e., in Figure 1, the crankshaft 22 rotates clockwise). If the force is continued to be applied to the first mechanism 3, it will operate until it reaches the state shown in Figure 1 (the state where the second connection point 32 is located at the far dead center FDC). In the process, via the rotating crankshaft 22, the second connection point 42 of the second mechanism 4 passes the state where it is located at the near dead center NDC (the state shown in Figure 6). After reaching the state shown in Figure 1, if the object to which an external force is applied is changed again to the second mechanism 4, the second connection point 42 is beyond the near-dead point NDC, causing the first connection point 41 to rotate in the direction of arrow 52.

[0103] In other words, the mechanism operates by applying force to the second mechanism 4 from the state in Figure 1 through the state in Figure 4 to the state in Figure 5, and by applying force to the first mechanism 3 from the state in Figure 5 through the state in Figure 6 to the state in Figure 1.

[0104] In this way, by alternately applying force to the first mechanism 3 and the second mechanism 4, the crankshaft 22 can be rotated in the same direction.

[0105] Furthermore, in the crank mechanism 1, the direction of rotation of the crankshaft 22 and the direction of rotation of the second connection point of the mechanism, which is subjected to force, around the third connection point are both clockwise and coincide. In other words, the mechanism is designed so that the direction in which the second connection point rotates due to the application of an external force coincides with the direction in which the crankshaft 22 rotates as a result.

[0106] Next, we will explain the case in which the crank mechanism 1 is operated so that the second connection point approaches the crankshaft 22. Operating the crank mechanism 1 so that the second connection point approaches the crankshaft 22 can be achieved, for example, by applying an external force to the second link. Specifically, a force may be applied to the second link 45 of the second mechanism 4 in Figure 4 in the negative Z-axis direction (downward; the direction indicated by F21) or in the lower right direction of Figure 4 (the direction indicated by F22). Note that the direction in which the force is applied can be any direction as long as it is in a direction that brings the second connection point closer to the crankshaft 22. In addition, a force may be applied to the first link 44 of the second mechanism 4.

[0107] An external force is applied to the first mechanism 3 until its second connection point 32 is at near-dead center (NDC). Then, the target of the force is switched to the second mechanism 4, and the force is applied to the second mechanism 4 until its second connection point 42 is at near-dead center (NDC). This process is repeated. This allows the crankshaft 22 to rotate continuously in the same direction.

[0108] Furthermore, while a force is applied to one mechanism, the other mechanism operates in conjunction via the crankshaft 22. Specifically, while a force is applied to one mechanism in a direction that brings the second connection point closer to the crankshaft 22, the other mechanism moves in a direction that moves the second connection point away from the crankshaft 22. In the other mechanism, after the second connection point crosses the far dead center (FDC) during its movement, it moves in a direction that brings it closer to the crankshaft 22.

[0109] This will be explained in detail with reference to Figures 1, 4, 5, and 6. When the crank mechanism 1 is operated so that the second connection point 32 approaches the crankshaft 22, the state of the crank mechanism 1 transitions in the order of Figures 4, 1, 6, and 5. By applying an external force to the first mechanism 3 (for example, the second link 35 of the first mechanism 3) so that the second connection point 32 approaches the near-dead point NDC, the state in which the second connection point 32 is located at the near-dead point NDC is reached (the state in Figure 4). Subsequently, when an external force is applied to the second mechanism 4 (for example, the second link 45 of the second mechanism 4) so ​​that the second connection point 42 approaches the near dead center NDC, the second connection point 42 rotates around the third connection point 43 in the direction of arrow 61. Since the second connection point 42 has passed the far dead center FDC, it rotates the first connection point 41 in the direction of arrow 62 and the crankshaft 22 in the direction of arrow 63 (i.e., the crankshaft 22 rotates counterclockwise). If an external force is continuously applied to the second mechanism 4, the crankshaft 22 continues to rotate and operates until the second connection point 42 reaches the near dead center NDC (the state in Figure 6) and then stops. In the process, the second connection point 32 of the first mechanism 3 swings via the rotating crankshaft 22 and passes the state where it is located at the far dead center FDC (the state in Figure 1). In other words, while a force is being applied to the second mechanism 4, the second connection point 32 of the first mechanism 3 on the opposite side passes the far dead center FDC.

[0110] Subsequently, the target of the external force is changed to the first mechanism 3. When a force is applied to the first mechanism 3 in a direction that moves the second connection point 32 closer to the near dead center (NDC), as shown in Figure 6, the second connection point 32 rotates around the third connection point 33 in the direction of arrow 64. Since the second connection point 32 has passed the far dead center (FDC), the first connection point 31 rotates in the direction of arrow 65 (the same direction as the rotation in the state transition from Figure 4 through Figure 1 to Figure 6), causing the crankshaft 22 to rotate in the direction of arrow 66 (i.e., the crankshaft 22 rotates counterclockwise). If the force is continued to be applied to the first mechanism 3, the second connection point 42 moves through the far dead center (FDC) state (the state in Figure 5) to the state in Figure 4 (the state where the second connection point 32 is located at the near dead center (NDC)). Subsequently, when the target of the external force is changed again to the second mechanism 4, the second connection point 42 has passed the far dead center FDC, causing the first connection point 41 to rotate in the direction of arrow 62.

[0111] In other words, the mechanism operates by applying force to the second mechanism 4 from the state in Figure 4 through the state in Figure 1 to the state in Figure 6, and by applying force to the first mechanism 3 from the state in Figure 6 through the state in Figure 5 to the state in Figure 4.

[0112] In this way, even when the crank mechanism 1 is operated so that the second connection point approaches the crankshaft 22, the crankshaft 22 can be rotated in the same direction by alternately applying force to the first mechanism 3 and the second mechanism 4.

[0113] Furthermore, even when the crank mechanism 1 is operated so that the second connection point approaches the crankshaft 22, the rotation direction of the crankshaft 22 and the rotation direction of the second connection point of the mechanism to which force is applied, around the third connection point, are the same. In other words, the mechanism is designed so that the direction in which the second connection point rotates due to the application of an external force coincides with the direction in which the crankshaft 22 rotates as a result.

[0114] The operation of the crank mechanism 1 will be explained in detail with reference to Figures 7, 8, and 9. Figure 7 is a schematic diagram illustrating the rotation trajectory of the second connection point in the crank mechanism 1 and the relationship between the far dead center (FDC) and the near dead center (NDC). Figure 8 is a schematic diagram illustrating the rotation of the crank arm. Figure 9 is a schematic diagram illustrating the rotation of the crank arm in the opposite direction. Note that the rotation of the second connection point shown in Figure 7 is also true for both the second connection point 32 and 42.

[0115] In Figures 7 and 8, reference numeral CR denotes a circle centered on the crankshaft 22, indicating the possible location of the first connection point. The radius of this circle is the effective length of the crank arm.

[0116] In Figure 7, reference numeral C31 indicates the possible location of the second connection point of the second link. This is the circumference of a circle centered at the third connection point with a radius of the effective length L2 of the second link. Note that the circumference indicated by reference numeral C31 represents the possible location of the second connection point when considering only the position of the third connection point and the effective length of the second link.

[0117] In Figure 7, reference numeral CF indicates the possible location of the far dead center FDC at the second connection point of the first link. This is the circumference centered on the crankshaft 22, with a radius equal to the sum of the effective length L1 of the first link and the effective length CL of the crank arm. The circumference indicated by reference numeral CF represents the possible location of the far dead center FDC when considering only the position of the crankshaft 22, the effective length of the first link, and the effective length of the crank arm.

[0118] In Figure 7, reference numeral CN indicates the location where the near-dead point NDC of the second connection point of the first link may exist. This is the circumference centered on the crankshaft 22 and whose radius is the effective length L1 of the first link minus the effective length CL of the crank arm. Note that the circumference indicated by reference numeral CN is the location where the near-dead point NDC may exist when considering only the position of the crankshaft 22, the effective length of the first link, and the effective length of the crank arm.

[0119] In Figure 7, reference numeral C32 indicates a set of possible positions where the second connection point of the first link can exist while moving between the far dead center (FDC) and the near dead center (NDC). This is the region between the circumference indicated by reference numeral CF and the circumference indicated by reference numeral CN. Note that the region indicated by reference numeral C32 is the region considering only the position of the crankshaft 22, the effective length of the first link, and the effective length of the crank arm.

[0120] In Figure 7, the trajectory indicated by reference numeral C30 is the rotational trajectory of the second connection point as it reciprocates between the far dead center (FDC) and the near dead center (NDC), taking into account the position of the crankshaft 22, the effective length of the first link, the effective length of the second link, and the effective length of the crank arm. This trajectory is the overlapping portion of the area indicated by reference numeral C32 and the circumference of reference numeral C31. In Figure 7, this trajectory is shown with a thicker line than the others.

[0121] As is clear from Figure 7, the second connection point rotates around the crankshaft 22 from the far dead center (FDC) to the near dead center (NDC). As a result, the direction from the second connection point to the crankshaft 22 at the near dead center (NDC) is different from the direction from the second connection point to the crankshaft 22 at the far dead center (FDC). More specifically, the phase difference between the intersection point P1 (position of the first connection point at the near dead center) of the line connecting the second connection point and the crankshaft 22 at the near dead center (NDC) and the rotation radius of the crank arm, and the intersection point P2 (position of the first connection point at the far dead center) of the line connecting the second connection point and the crankshaft 22 at the far dead center (FDC) is less than 180 degrees. As a result, while a force is applied to one mechanism causing a 180-degree phase advance, the other mechanism passes the near dead center (NDC).

[0122] Figure 8 is an enlarged view of reference numeral CR in Figure 7 and its interior. Reference numeral 71 is the position of the crank arm of one of the first mechanism 3 and the second mechanism 4 when the second connection point is at the far dead center (FDC). Reference numeral 72 is the position of the crank arm of the other of the first mechanism 3 and the second mechanism 4 at that time. Reference numeral 73 is the position of the crank arm of one of the first mechanisms when the second connection point is at the near dead center (NDC). For example, reference numeral 71 is the position of the crank arm 30 of the first mechanism 3 in the state shown in Figure 1 (the first mechanism 3 is at the far dead center), reference numeral 72 is the position of the crank arm 40 of the second mechanism 4 in the state shown in Figure 1, and reference numeral 73 is the position of the crank arm 30 of the first mechanism 3 in the state shown in Figure 4 (the first mechanism 3 is at the near dead center).

[0123] Referring to Figure 8, the operation of the crank mechanism 1 when the second connection point 32 is moved away from the crankshaft 22 will be explained. When the crank arm 30 of the first mechanism 3 is at the position of reference numeral 71 (the state in Figure 1, where the second connection point 32 is at the far dead center FDC), the crank arm 40 of the second mechanism 4, which is 180 degrees out of phase with respect to the crank arm 30 of the first mechanism 3, is at the position of reference numeral 72. In this state, when a force is applied to the second mechanism 4 in a direction that causes the second connection point 42 to move toward the far dead center FDC, the crank arm 40 of the second mechanism 4 rotates as indicated by reference numeral R2. If the force is continued to be applied to the second mechanism 4, the crank arm 40 of the second mechanism 4 rotates to the position of reference numeral 71 (the position where the second connection point 42 is at the far dead center FDC) and stops. During this time, the crank arm 30 of the first mechanism 3 moves from the position indicated by reference numeral R1, past the position indicated by reference numeral 71 (where the second connection point 32 is at the far dead center FDC), past the position indicated by reference numeral 73 (where the second connection point 32 is at the near dead center NDC), to the position indicated by reference numeral 72. In this state, if a force is applied to the first mechanism 3 in a direction that causes the second connection point 32 to move toward the far dead center FDC, the crank arm 30 of the first mechanism 3 rotates in the direction indicated by reference numeral R2 because it has passed the position indicated by reference numeral 73 (where the second connection point 32 is at the near dead center NDC). As a result, the crank shaft 22 rotates in the direction indicated by reference numeral R2. In this way, by switching the mechanism to which force is applied, the crank shaft 22 can be kept rotating in the same direction.

[0124] Referring to Figure 9, the operation of the crank mechanism 1 when the second connection point is moved toward the crankshaft 22 will be explained. In Figure 9, reference numeral 81 denotes the position of the crank arm of one of the first mechanism 3 and the second mechanism 4 when the second connection point is located at near dead center (NDC). Reference numeral 82 denotes the position of the crank arm of the other of the first mechanism 3 and the second mechanism 4 at that time. Reference numeral 83 denotes the position of the crank arm of the one of the first mechanism 3 when the second connection point is located at far dead center (FDC). That is, reference numeral 81 denotes the position of the crank arm 30 of the first mechanism 3 in the state of Figure 4 (when the first mechanism 3 is at near dead center (NDC)), reference numeral 82 denotes the position of the crank arm 40 of the second mechanism 4 in the state of Figure 4, and reference numeral 83 denotes the position of the crank arm 30 of the first mechanism 3 in the state of Figure 1 (when the first mechanism 3 is at far dead center (FDC)).

[0125] When the crank arm 30 of the first mechanism 3 is at the position indicated by reference numeral 81 (when the second connection point 32 is at the near-dead point NDC), the crank arm 40 of the second mechanism 4, which is 180 degrees out of phase with respect to the crank arm 30 of the first mechanism 3, is at the position indicated by reference numeral 82. In this state, when a force is applied to the second mechanism 4 in a direction such that the second connection point 42 is toward the near-dead point NDC, the crank arm 40 of the second mechanism 4 rotates as indicated by reference numeral R4. If the force is continued to be applied to the second mechanism 4, the crank arm 40 of the second mechanism 4 rotates to the position indicated by reference numeral 81 (the position where the second connection point 42 is at the near-dead point NDC) and stops. During this time, the crank arm 30 of the first mechanism 3 rotates as indicated by reference numeral R3, moving from the position of reference numeral 81 (where the second connection point 32 is at near dead center NDC) past the position of reference numeral 83 (where the second connection point 32 is at far dead center FDC) to the position of reference numeral 82. In this state, if a force is applied to the first mechanism 3 in a direction that causes the second connection point 32 to move toward near dead center NDC, the crank arm 30 of the first mechanism 3 rotates as indicated by reference numeral R4, since it has passed the position of reference numeral 83 (where the second connection point 32 is at far dead center FDC). As a result, the crankshaft 22 rotates in the direction of reference numeral R4. In this way, even when moving the second connection point 32 toward the crankshaft 22, the crank mechanism 1 can continue to rotate the crankshaft 22 in the same direction by switching the mechanism that applies force.

[0126] Referring to Figures 10 and 11, a crank mechanism (reference example) that is different from crank mechanism 1 and is intended as a reference example for comparison with the crank mechanism of this disclosure will be described. In this crank mechanism, the second connection point at far dead center (FDC) and the second connection point at near dead center (NDC) are in the same direction when viewed from the crank shaft 22, and it does not have the same effects as crank mechanism 1. Figure 10 is a schematic side view showing the state in the crank mechanism (reference example) where the second connection point 32 of the first mechanism 3 is at far dead center (FDC) and the second connection point 42 of the second mechanism 4 is at near dead center (NDC). Figure 11 is a schematic diagram for explaining the rotation of the crank arm in the crank mechanism shown in Figure 10.

[0127] In the crank mechanism shown in Figure 10 (reference example), when the second connection point of one of the first mechanism 3 and the second mechanism 4 is located at the far dead center FDC, the second connection point of the other of the first mechanism 3 and the second mechanism 4 is located at the near dead center NDC. In this case, as shown in Figure 11, the far dead center FDC and the near dead center NDC of each of the first mechanism 3 and the second mechanism 4 are located on the straight line SL1. The meaning of each reference numeral in Figure 11 is the same as the meaning of each reference numeral in Figure 7.

[0128] In this case, when the second connection point of one mechanism is at the far dead center (FDC), the second connection point of the other mechanism is at the near dead center (NDC), making continuous rotation of the crankshaft 22 difficult. To avoid this, the effective length CL of the crank arm, the effective length L1 of the first link, the effective length L2 of the second link, and the base distance D should be designed so that they do not have the relationship shown in Figures 10 and 11 (in other words, the second connection point at the far dead center (FDC) and the second connection point at the near dead center (NDC) are in the same direction relative to the crankshaft 22). However, such a relationship is extremely rare and is not something that should be particularly considered when designing each length and distance.

[0129] As mentioned above, in the crank mechanism 1 shown in Figure 1, the direction in which the crankshaft 22 rotates coincides with the direction in which the second connection point rotates around the third connection point in the mechanism on the side where the force is applied. In order to make the direction of rotation of the crankshaft 22 coincide with the direction in which the second connection point rotates around the third connection point in the mechanism on the side where the force is applied, as shown in Figure 7, the second connection point at near dead center (NDC) should be on the opposite side of the third connection points 33 and 43, with reference to the straight line SL1 connecting the second connection point at far dead center (FDC) and the crankshaft 22.

[0130] As shown in Figure 7, when the direction of rotation of the crankshaft 22 coincides with the direction in which the second connection point rotates around the third connection point in the mechanism on the side where the force is applied, the rotational trajectory C30 of the second connection point becomes a similar trajectory that bulges to the same side as the rotational trajectory of the first connection point that rotates the crankshaft 22, and the force applied from the second connection point to the first connection point can naturally rotate the crankshaft 22.

[0131] (Walking mechanism) Figure 12 is a schematic side view showing a walking mechanism 10 according to one embodiment of the present disclosure. In this disclosure, "walking mechanism 10" refers to one embodiment of the walking mechanism. The walking mechanism 10 utilizes a mechanism similar to the crank mechanism 1 described above. The walking mechanism 10 is a passive walking mechanism. That is, the walking mechanism 10 is a mechanism that walks by grasping the torso or the like with a hand and moving it forward, thereby transmitting the force applied from the walking surface 100 to the grounded legs 342, 442 to the crankshaft 22, which rotates the crankshaft 22.

[0132] Walking mechanism 10, and walking mechanism 1 (see Figure 30), described later, are shaped to resemble a person, animal, robot, etc. When the torso moves forward due to a user grasping the torso, some power source pushing / pulling the torso (such as a battery-operated toy car), or gravity when placed on an incline (hereinafter also referred to as "user, etc."), its legs reproduce the movement of a person's legs. The torso is the part corresponding to the torso of a person, animal, robot, etc. In each figure, the torso is shown as a part thereof. Although not shown, walking mechanisms 10 and 1 may also have a head, arms, etc.

[0133] The crank mechanism 1A in the walking mechanism 10 has the same configuration as the crank mechanism 1 described above and performs the operation as described above, but differs from the crank mechanism 1 in that the torso 2A corresponding to the support 2 and the first links 34A and 44A have a bent shape. The second link may also have a bent shape.

[0134] In the following, the body 2A, main body 21A, and crankshaft 22A of the crank mechanism 1A correspond to the support 2, main body 21, and crankshaft 22 of the crank mechanism 1, respectively.

[0135] Furthermore, the first mechanism 3A, crank arm 30A, first connection point 31A, second connection point 32A, third connection point 33A, first link 34A, and second link 35A in the crank mechanism 1A correspond to the first mechanism 3, crank arm 30, first connection point 31, second connection point 32, third connection point 33, first link 34, and second link 35 in the crank mechanism 1, respectively.

[0136] Furthermore, the second mechanism 4A, crank arm 40A, first connection point 41A, second connection point 42A, third connection point 43A, first link 44A, and second link 45A in the crank mechanism 1A correspond to the second mechanism 4, crank arm 40, first connection point 41, second connection point 42, third connection point 43, first link 44, and second link 45 in the crank mechanism 1, respectively.

[0137] In this embodiment, the third connection points 33A and 43A are positioned above the crankshaft 22A (in a direction away from the walking surface 100 with respect to the walking surface 100).

[0138] The first link 34A has a main part 341 and a leg part 342, and in this embodiment, it has a bent shape. The main part 341 is the part of the first link 34A that connects to the crank arm 30A and the second link 35A. The leg part 342 is the part that extends in a predetermined direction from a predetermined position of the main part 341 (which may be the end, an intermediate part, or it may extend from multiple positions), and in this embodiment, it extends diagonally from the end of the main part 341. The main part 341 and the leg part 342 may be formed integrally, or they may be fixedly connected as separate parts. The tip of the leg part 342 is the part that makes contact with the walking surface 100.

[0139] The first link 44A has a main section 441 and a leg section 442, and has the same configuration as the first link 34A.

[0140] The leg portions 342 and 442 are examples of fixed parts. At least one of the first links 34 and 44 of the crank mechanism 1 described above may also have a fixed part.

[0141] The leg portion 342 of the first mechanism 3A and the leg portion 442 of the second mechanism 4A have the same configuration. The configuration of the leg portion 342 of the first mechanism 3A will be described below. The description of the configuration of the leg portion 442 of the second mechanism 4A will be omitted in principle and will be explained as needed.

[0142] The leg portion 342 comprises a connecting portion 343 and a ground contact portion 344. The ground contact portion 344 is the part that contacts the walking surface 100. The connecting portion 343 is the part that connects the ground contact portion 344 and the main portion 341. The ground contact portion 344 is integrally formed with the connecting portion 343 or is fixedly attached to it. The connecting portion 343 is integrally formed with the main portion 341 or is fixedly attached to it. The connecting portion 343 extends downward from the main portion 341 (in the opposite direction to the Z-axis direction). In this embodiment, one end of the connecting portion 343 is fixed to the main portion 341, and the other end of the connecting portion 343 is fixed to the ground contact portion 344. The leg portion 442 comprises a connecting portion 443 and a ground contact portion 444, with the connecting portion 443 corresponding to the connecting portion 343 and the ground contact portion 444 corresponding to the ground contact portion 344.

[0143] The main body 341 and the leg portion 342 may be formed integrally, or they may be separate parts fixed to each other. Similarly, the connecting portion 343 and the ground contact portion 344 may be formed integrally, or they may be separate parts fixed to each other. In either case, whether the main body 341 and the leg portion 342 are formed integrally or the leg portion 342 is a separate part fixedly attached to the main body 341, the leg portion 342 operates integrally with the main body 341, and the leg portion 342 is part of the first link 34A.

[0144] The connecting portion 343 extends toward the walking surface 100. The contact portion 344 extends forward from the connecting portion 343.

[0145] The grounding portion 344 may extend in a direction perpendicular to the connection portion 343, or it may extend in an inclined direction.

[0146] The grounding portion 344 may extend both forward and backward from the connecting portion 343. Alternatively, for example, the grounding portion 344 may protrude from the connecting portion 343 over its entire circumference in a direction perpendicular to the Z-axis direction.

[0147] The leg portion 342 is configured to make contact with the walking surface 100 after the second connection point 32A of the first mechanism 3A has passed the near-dead point NDC, and before the second connection point 42A of the second mechanism 4A has reached the far-dead point FDC (before the leg portion 442 leaves the walking surface 100). Furthermore, the leg portion 442 is configured to make contact with the walking surface 100 after the second connection point 42A of the second mechanism 4A has passed the near-dead point NDC, and before the second connection point 32A of the first mechanism 3A has reached the far-dead point FDC (before the leg portion 342 leaves the walking surface 100).

[0148] Furthermore, the leg portion 342 of the first mechanism 3A is configured to move away from the walking surface 100 before the second connection point 32A reaches the far dead center FDC and after the second connection point 42A has passed the near dead center NDC. Similarly, the leg portion 442 of the second mechanism 4A is configured to move away from the walking surface 100 before the second connection point 42A reaches the far dead center FDC and after the second connection point 42A has passed the near dead center NDC.

[0149] To achieve the configuration described above, for example, the length of the line segment connecting the first and second connection points in the main parts 341 and 441, the mounting positions of the legs 342 and 442 in the main parts 341 and 441, the length of the legs 342 and 442, and the direction and length of the parts of the legs 342 and 442 that come into contact with the walking surface 100 (contact surfaces 345 and 445, described later) should be adjusted or designed.

[0150] With this configuration, the walking mechanism 10 operates as follows: The leg portion 342 of the first mechanism 3A makes contact with the walking surface 100 and receives a force from the walking surface 100, causing the second connection point 32A to move toward the far dead center FDC. Consequently, the second connection point 42A of the second mechanism 4A crosses the near dead center NDC. Subsequently, the leg portion 442 of the second mechanism 4A makes contact with the walking surface 100 and begins to receive a force from the walking surface 100, while the leg portion 342 leaves the walking surface 100 before the second connection point 32A reaches the far dead center FDC. Subsequently, the leg portion 442 receives a force from the walking surface 100, causing the second connection point 42A to move toward the far dead center FDC. At this point, since the second connection point 42A has crossed the near dead center NDC, the crankshaft 22A continues to rotate in the same direction.

[0151] (Operation of the walking mechanism) Figures 12 to 17 are schematic side views of the walking mechanism 10. The walking mechanism 10 moves forward by grasping its torso with its hands, etc., and transitions sequentially to the states shown in Figure 12, Figure 13, Figure 14, Figure 15, Figure 16, and Figure 17.

[0152] Figure 13 is a side view showing the state after the walking mechanism 10 has been made to walk from the state shown in Figure 12, with the leg portion 442 of the second mechanism 4A receiving a force from the walking surface 100 and moving backward, and consequently the leg portion 342 of the first mechanism 3A moving away from the walking surface 100. Figure 14 is a side view showing the state after the walking mechanism 10 has been made to walk further from the state shown in Figure 13, with the leg portion 442 of the second mechanism 4A receiving a force from the walking surface 100 and moving further backward, and consequently the leg portion 342 of the first mechanism 3A moving forward. Figure 15 is a side view showing the state just before the leg portion 442 of the second mechanism 4A receives a force from the walking surface 100 and moves further backward and leaves the walking surface 100, and consequently the moment when the leg portion 342 of the first mechanism 3A makes contact with the walking surface 100. Figure 16 is a side view showing the state after the walking mechanism 10 has been made to walk further from the state shown in Figure 15, with the leg portion 342 of the first mechanism 3A moving backward due to a force from the walking surface 100, and consequently, the leg portion 442 of the second mechanism 4A moving away from the walking surface 100. Figure 17 is a side view showing the state after the walking mechanism 10 has been made to walk further from the state shown in Figure 16, with the leg portion 342 of the first mechanism 3A moving further backward due to a force from the walking surface 100, and consequently, the leg portion 442 of the second mechanism 4A moving forward.

[0153] Figure 12 shows the moment when the contact point 444 of the second mechanism 4A makes contact with the walking surface 100, and just before the contact point 344 of the first mechanism 3A leaves the walking surface 100.

[0154] In the state shown in Figure 12, the second connection point 32A of the first mechanism 3A is close to the far dead center FDC, but has not yet reached it. In the state shown in Figure 12, the second connection point 42A of the first mechanism 3A has passed the near dead center NDC. Up until the state shown in Figure 12, the leg portion 342 of the first mechanism 3A was receiving force from the walking surface 100. However, since the leg portion 342 leaves the walking surface 100 before the second connection point 32A reaches the far dead center FDC, the second connection point 32A cannot receive force up to the far dead center FDC. At this point, the leg portion 442 of the second mechanism 4A is in contact with the ground, and the second connection point 42A has passed the near dead center NDC. Therefore, the leg portion 442 receives force from the walking surface 100, which can rotate the crankshaft 22A in the same direction.

[0155] The operation of crank mechanism 1A is the same as that of crank mechanism 1. However, in crank mechanism 1A, when walking on the walking surface 100, no force is applied to the first link until the second connection point reaches the far dead center FDC; the force is applied to the first link only up to that point.

[0156] In the following description, the operation of the legs 342 and 442 of the crank mechanism 1A will be explained, while the operation of other parts of the crank mechanism 1A will be omitted in principle and explained as needed.

[0157] When the crank mechanism 1A is in the state shown in Figure 12, the leg portion 342 of the first mechanism 3A is located behind the torso 2A, and the leg portion 442 of the second mechanism 4A is located in front of the torso 2A. At this time, the front end (the end in the positive direction of the X-axis) of the contact portion 344 of the leg portion 342 of the first mechanism 3A and the rear end (the end in the negative direction of the X-axis) of the contact portion 444 of the leg portion 442 of the second mechanism 4A are in contact with the walking surface 100. Also at this time, the second connection point 32A of the first mechanism 3A is located near the far dead center FDC. On the other hand, the second connection point 42A of the second mechanism 4A is beyond the near dead center NDC.

[0158] In the state shown in Figure 12, for example, if the user grasps the torso 2A and moves the torso 2A forward, the force received by the contact portion 444 of the second mechanism 4A, which is in contact with the walking surface 100, from the walking surface 100 causes the first link 44A of the second mechanism 4A to move backward relative to the torso 2A. As a result, the second connection point 42A of the second mechanism 4A rotates backward around the third connection point 43A in the direction of arrow 101. Since the second connection point 42A has passed the near dead center NDC, the first connection point 41A rotates in the direction of arrow 102, and the crankshaft 22A rotates in the direction of arrow 103. Due to this rotation of the second connection point 42A, the first connection point 41A, and the crankshaft 22A, the second connection point 42A moves away from the crankshaft 22A and towards the far dead center FDC.

[0159] As the crankshaft 22 rotates in the direction of arrow 103, the first connection point 31A of the first mechanism 3A rotates in the direction of arrow 104, and the second connection point 32A rotates forward around the third connection point 33A as shown by arrow 105.

[0160] Due to the rotation of the crankshaft 22A caused by the contact point 444 of the second mechanism 4A being in contact with the ground, the leg portion 342 rotates forward while moving away from the walking surface 100.

[0161] When the user grasps the walking mechanism 10 and moves it further forward, the state transitions from the state in Figure 12 to the state in Figure 13. Specifically, the ground contact portion 444 of the second mechanism 4A receives a force from the walking surface 100, causing the leg portion 442 to move further backward. The rotation of the crankshaft 22A as a result causes the ground contact portion 344 of the first mechanism 3A to move away from the walking surface 100 while continuing to move forward. During this state transition, the rear end of the ground contact portion 444 of the second mechanism 4A moves away from the walking surface 100, while the front end (in other words, the toe portion) of the ground contact portion 444 of the second mechanism 4A makes contact with the walking surface 100. In this way, the force from the ground contact portion 444 of the second mechanism 4A as the walking mechanism 10 moves forward causes the leg portion 442 to continue rotating backward and the leg portion 342 to continue rotating forward.

[0162] Furthermore, when the user grasps the walking mechanism 10 and moves it forward, the crank mechanism 1A transitions from the state shown in Figure 13 to the state shown in Figure 14. Specifically, the contact point 444 of the second mechanism 4A receives a force from the walking surface 100, causing the leg portion 442 to move further backward, and the resulting rotation of the crank shaft 22A causes the leg portion 342 to move further forward. Also, during this state transition, the second connection point 32A of the first mechanism 3A approaches the near-dead point NDC and reaches the near-dead point NDC in the state shown in Figure 14. On the other hand, the second connection point 42A of the second mechanism 4A approaches the far-dead point FDC, but does not reach the far-dead point FDC in the state shown in Figure 14. Also, in the state shown in Figure 14, the contact point 344 of the first mechanism 3A is not in contact with the ground.

[0163] Furthermore, when the user grasps the walking mechanism 10 and moves it forward, the crank mechanism 1A transitions from the state shown in Figure 14 to the state shown in Figure 15. Specifically, the leg portion 442 of the second mechanism 4A receives force from the walking surface 100 and moves further backward, reaching a state just before leaving the walking surface 100. The rotation of the crank shaft 22A as a result causes the rear end of the contact portion 344 of the first mechanism 3A to make contact with the walking surface 100. During this state transition, the second connection point 32A of the first mechanism 3A passes the near-dead point NDC, and the contact portion 344 of the leg portion 342 of the first mechanism 3A makes contact with the ground afterward.

[0164] In the state shown in Figure 15, the second connection point 42A of the second mechanism 4A is located slightly before the far dead center FDC.

[0165] In other words, by the time the second connection point 42A in the second mechanism 4A reaches the far dead center FDC, the ground contact portion 344 of the leg portion 342 in the first mechanism 3A has made contact with the ground, and the second connection point 32A has passed the near dead center NDC.

[0166] With its ground contact portion 344 in contact with the walking surface 100 and its second connection point 32A positioned beyond the near-dead point (NDC), the leg portion 342 of the first mechanism 3A rotates backward around the point of contact between the ground contact portion 344 and the walking surface 100 due to the force acting from the walking surface 100. Since the second connection point 32A is beyond the near-dead point (NDC), the first connection point 31A of the first mechanism 3A rotates clockwise. The second mechanism 4A operates via the rotation of the crankshaft 22A by the first mechanism 3A, and the ground contact portion 444 of the second mechanism 4A moves away from the walking surface 100. Subsequently, the leg portion 442 of the second mechanism 4A moves forward as the crankshaft 22A rotates further backward due to the movement of the leg portion 342 of the first mechanism 3A.

[0167] Furthermore, when the user grasps the walking mechanism 10 and moves it forward, the walking mechanism 10 transitions from Figure 15 to Figure 16, then from Figure 16 to Figure 17, and then from Figure 17 to Figure 12. Specifically, in the transition from Figure 15 to Figure 16, the leg portion 342 of the first mechanism 3A receives a force from the walking surface 100 and moves backward, and consequently, the leg portion 442 of the second mechanism 4A moves away from the walking surface 100. In the transition from Figure 16 to Figure 17, the leg portion 342 of the first mechanism 3A receives a force from the walking surface 100 and moves further backward, and consequently, the leg portion 442 of the second mechanism 4A moves forward. Then, in the transition from Figure 17 to Figure 12, the leg portion 342 of the first mechanism 3A receives force from the walking surface 100 and moves further backward, reaching a state just before leaving the walking surface 100. Consequently, the leg portion 442 of the second mechanism 4A moves forward and makes contact with the walking surface 100. This is similar to the state transitions from Figure 12 to Figure 13, then from Figure 13 to Figure 14, and then from Figure 14 to Figure 15, although the difference is whether the first mechanism 3A is in contact with the ground and rotating the crankshaft 22A, or whether the second mechanism 4A is in contact with the ground and rotating the crankshaft 22A. As the user grasps the walking mechanism 10 and continues to move it forward, the mechanism receiving force from the walking surface 100 switches in this way, the crankshaft 22A continues to rotate clockwise, and the legs 342 and 442 of the first mechanism 3A and the second mechanism 4A operate in a manner that mimics the movements of a person or animal.

[0168] The above describes the case where the walking mechanism 10 is moved forward (to the right on the plane of Figure 12), but the walking mechanism 10 can also be moved backward (to the left on the plane of Figure 12). In other words, the walking mechanism 10 is capable of walking backward. In the case of walking backward, the contact surface that is in contact with the walking surface 100 receives a force from the walking surface 100 in the direction from left to right on the plane of Figure 12, causing the crankshaft 22A to rotate counterclockwise. The second connection point for the leg that is in contact with the walking surface 100 moves in the direction of the near dead center NDC and leaves the walking surface 100 before reaching the near dead center NDC. However, before that, the second connection point for the opposite leg has passed the far dead center FDC, and the contact surface of that opposite leg makes contact with the walking surface 100 and receives a force from the walking surface 100 in the direction from left to right on the plane of Figure 12, causing the crankshaft 22A to rotate in the same direction (counterclockwise).

[0169] The walking mechanism 10 is configured such that the second connection point is located on the opposite side of the direction of travel relative to the straight line connecting the third connection point and the crank axis 22A. However, the second connection point may also be located on the same side as the direction of travel relative to the straight line connecting the third connection point and the crank axis 22A.

[0170] (Modified example of the contact point of a walking mechanism) Figure 18 is a schematic side view showing a modified example of the ground contact portion of the walking mechanism of this disclosure.

[0171] As shown in the modified walking mechanism 10A in Figure 18, the central portion 3451 of the contact surface 345 of the contact portion 344 of the leg portion 342 in the front-rear direction (the X-axis direction, which is the walking direction of the walking mechanism) may bulge out relative to the other parts of the contact surface 345 (for example, the front end 3452 and rear end 3453 of the contact surface 345 in the front-rear direction). Similarly, the central portion 4451 of the contact surface 445 of the contact portion 444 of the leg portion 442 in the front-rear direction may bulge out relative to the other parts of the contact surface 445 (for example, the front end 4452 and rear end 4453 of the contact surface 445 in the X-axis direction). The contact surfaces 345, 445 are the surfaces of the legs 342, 442 that can come into contact with the walking surface 100. By configuring the back surface of the contact portion in this way, the contact of the contact portion with the walking surface 100 becomes smoother, eliminating vertical movement associated with the forward movement of the walking mechanism, and also making the rotation of the crankshaft 22A smoother.

[0172] Figure 19 is a schematic side view showing a modified example of the ground contact portion of the walking mechanism of this disclosure.

[0173] The contact surface 345 of the contact portion 344 of the leg portion 342 may be fitted with a member for preventing slippage, or it may be treated to prevent slippage. For example, a member such as rubber with a high coefficient of friction may be fitted to all or part of the contact surface 345, or the coefficient of friction may be increased by sandblasting. In a passive walking mechanism, the legs need to receive the force received from the walking surface 100, and with this configuration, the force received from the walking surface 100 can be firmly received.

[0174] Furthermore, the coefficient of friction of a portion of the contact surface 345 may be higher than that of other portions. Specifically, as shown in the modified walking mechanism 10B in Figure 19, the coefficient of friction of both ends (front end 3452 and rear end 3453) of the contact surface 345 of the contact portion 344 of the leg 342 in the front-rear direction may be configured to be higher than the coefficient of friction of the central part 3451 of the contact surface 345 in the front-rear direction. Similarly, the coefficient of friction of both ends (front end 4452 and rear end 4453) of the contact surface 445 of the contact portion 444 of the leg 442 in the front-rear direction may be configured to be higher than the coefficient of friction of the central part 4451 of the contact surface 445 in the X-axis direction. In the configuration shown in Figure 19, for example, the central parts 3451, 4451 with low coefficients of friction are made of a resin such as polyethylene terephthalate, and the front end parts 3452, 4452 and rear end parts 3453, 4453 with high coefficients of friction are made of a resin such as rubber. Furthermore, the coefficient of friction in the central part may be increased by, for example, applying sandblasting treatment to both ends of the contact surface 345 in the front-rear direction.

[0175] Figure 20 is a schematic bottom view showing a modified example of the contact surface of the walking mechanism of this disclosure.

[0176] As shown in the modified walking mechanism 10C in Figure 20, the coefficient of friction of the outer portion 3455 in the left-right direction (Y-axis direction (the axis direction of the crank axis 22 and the width direction of the walking mechanism)) of the contact surface 345 of the contact portion 344 of the leg portion 342 may be lower than the coefficient of friction of the inner portion 3454 in the left-right direction of the contact surface 345. Similarly, the coefficient of friction of the outer portion 4455 in the left-right direction of the contact surface 445 of the contact portion 444 of the leg portion 442 may be lower than the coefficient of friction of the inner portion 4454 in the left-right direction of the contact surface 445. In the configuration shown in Figure 20, for example, the inner portions 3454 and 4454 with a high coefficient of friction are made of rubber or the like, and the outer portions 3455 and 4455 with a low coefficient of friction are made of resin such as polyethylene terephthalate.

[0177] If the user grasps and moves the support 2 while it is tilted from side to side, the outer side of the contact point on the ground while the leg is raised and moving forward may come into contact with the walking surface 100. With the above configuration, even in such a case, the contact point on the ground while the leg is raised and moving can move forward without getting caught on the floor.

[0178] Conversely to the configuration shown in Figure 20, the coefficient of friction of the outer portions 3455 and 4455 may be higher than that of the inner portions 3454 and 4454.

[0179] (bicycle) Figures 21 to 29 will be used to describe the bicycle 500 using the crank mechanism 1. In the following description, when "bicycle 500" is referred to, it means the bicycle in this embodiment. Bicycle 50 has a mechanism similar to the crank mechanism 1 described above.

[0180] Referring to Figures 21 and 22, each element of the bicycle 500 will be described. The frame 501 corresponds to the support 2 in the crank mechanism 1 described above, the crank axle 502 corresponds to the crank axle 22, the crank arms 503R and 503L correspond to the crank arms 30 and 40 respectively, the first links 504R and 504L correspond to the first links 34 and 44 respectively, the second links 505R and 505L correspond to the second links 35 and 45 respectively, the first connection points 601R and 601L correspond to the first connection points 31 and 41 respectively, the second connection points 602R and 602L correspond to the second connection points 32 and 42 respectively, and the third connection points 603R and 603L correspond to the third connection points 33 and 43 respectively.

[0181] The mechanism consisting of crank arm 503R, first link 504R, and second link 505R is called the first mechanism 700R. The mechanism consisting of crank arm 503L, first link 504L, and second link 505L is called the second mechanism 700L. The first mechanism 700R corresponds to the first mechanism 3 in the crank mechanism 1 described above, and the second mechanism 700L corresponds to the second mechanism 4. In Figure 21, the first mechanism 700R is located on the near side of the page, and the second mechanism 700L is located on the far side of the page. In the following, when it is not necessary to distinguish between crank arm 503R and crank arm 503L, they may be collectively referred to as "crank arm 503". Similarly, when it is not necessary to distinguish between first link 504R and first link 504L, they may be collectively referred to as "first link 504". Furthermore, when there is no need to distinguish between the second link 505R and the second link 505L, they may be collectively referred to as "second link 505." Similarly, when there is no need to distinguish between the first connection point 601R and the first connection point 601L, they may be collectively referred to as "first connection point 601." Similarly, when there is no need to distinguish between the second connection point 602R and the second connection point 602L, they may be collectively referred to as "second connection point 602." Similarly, when there is no need to distinguish between the third connection point 603R and the third connection point 603L, they may be collectively referred to as "third connection point 603."

[0182] The bicycle 500 is equipped with a gear 801 similar to that of a normal bicycle. As shown in Figures 28 and 29, the gear 801 is fixedly attached to the crank axle 502 on one side of the frame 501 (for example, the right side when the bicycle is moving forward), at a position between the frame 501 and the crank arm 503, so as to rotate with the rotation of the crank axle 502. Although not shown, the bicycle 500 is also equipped with a gear on the rear wheel, similar to a normal bicycle, and the gear 801 and the gear on the rear wheel are connected by a chain or the like, so that the rear wheel rotates as the crank axle 502 rotates.

[0183] As shown in Figure 21, the bicycle 500 is equipped with pedals 901R and 901L, similar to those on a normal bicycle. Pedal 901R is the pedal pressed by the right foot and is rotatably connected to the first link 504R and the second link 505R at the second connection point 602R. Pedal 901L is the pedal pressed by the left foot and is rotatably connected to the first link 504L and the second link 505L at the second connection point 602L. When the user presses pedal 901R with their right foot, pedal 901R moves downward, and when the user presses pedal 901L with their left foot, pedal 901L moves downward.

[0184] Figure 21 is a side view of bicycle 500 showing the state when the user presses the pedal 901R with their right foot and the second connection point 602R reaches its near-dead point (the state in which the first connection point 601R, the crank axis 502, and the second connection point 602R are in a straight line). When this state is reached, the first mechanism 700R will not move any further even if the pedal 901R is pressed.

[0185] In the state shown in Figure 21, when the user changes the foot pressing on pedal 901 to the left foot and presses on pedal 901L with the left foot, the state transitions to that shown in Figure 22, and pedal 901L moves downward while the crank shaft 502 rotates (clockwise in the plane of Figure 21). During this time, pedal 901R moves upward as the crank shaft 502 rotates.

[0186] If the user presses pedal 901L further from the state shown in Figure 22, the state transitions to Figure 24 via Figure 23. During this time, pedal 901L moves further downward, and crankshaft 502 rotates further (rotating further to the right in the plane of Figure 22). During this time, pedal 901R moves further upward as crankshaft 502 rotates.

[0187] If the user presses pedal 901L further from the state shown in Figure 24, the system transitions to the state shown in Figure 25, where pedal 901L moves further downward and crankshaft 502 rotates further (rotating further to the right in the plane of Figure 22). During this time, pedal 901R moves further upward as crankshaft 502 rotates. In the state shown in Figure 25, the crankshaft 502, the first connection point 601R, and the second connection point 602R in the first mechanism 700R are approaching a state where they are in a straight line (far dead center state).

[0188] If the user presses pedal 901L further from the state shown in Figure 25, the state transitions to that shown in Figure 26, where pedal 901L moves further downward and crankshaft 502 rotates further (rotating further to the right in the plane of Figure 22). During this time, pedal 901R moves further upward as crankshaft 502 rotates. In the state shown in Figure 26, the crankshaft 502, the first connection point 601R, and the second connection point 602R in the first mechanism 700R are in a straight line, beyond the far dead center state.

[0189] If the user presses pedal 901L further from the state shown in Figure 26, the pedal transitions to the state shown in Figure 27, where pedal 901L moves further downward to reach the near-dead point (the state where the first connection point 601L, crankshaft 502, and second connection point 602L are in a straight line), and pressing pedal 901L will not move it any further. During this time, crankshaft 502 rotates further (rotating further to the right in the plane of Figure 22), and pedal 901R moves further upward as crankshaft 502 rotates.

[0190] In the state shown in Figure 27, when the user changes the foot pressing on pedal 901 to the right foot and presses on pedal 901R with the right foot, pedal 901R moves downward, and since the first mechanism 700R has passed the far dead center, the crankshaft 502 continues to rotate to the right. The state shown in Figure 27 is the same as the state shown in Figure 21, except that the states of the first mechanism 700R and the second mechanism 700L are swapped.

[0191] From the state shown in Figure 27, pressing pedal 901R further will cause the same operation as described above using Figures 22 onwards (the operation of the first mechanism 700R and the second mechanism 700L are reversed). By continuing to press pedal 901R, the first mechanism 700R will reach a near-dead point, and pedal 901R will no longer move downwards. At this point, by changing the foot used to press pedal 901L, the operation described above using Figures 21 to 27 will occur.

[0192] In this way, the bicycle 500 can be propelled forward by continuously rotating the crank axle 502 in the same direction by alternately pressing down with the left and right feet. Since the bicycle 500 does not need to rotate the pedals 901R and L 360 degrees around the crank axle 502, the pedals 90R and L can be positioned farther away from the crank axle, in which case the force applied to the crank axle 502 can be increased.

[0193] (Walking mechanism of another embodiment) Figure 30 is a schematic side view showing the walking mechanism 1. In the following description of the walking mechanism of a different embodiment, the reference numerals will be renumbered. There is no relationship with the reference numerals used in the above-described embodiments and the modified examples described later (i.e., embodiments other than the walking mechanism of the different embodiment). As shown in Figure 30, the walking mechanism 1 includes a torso 10, a right mechanism 20(R), a left mechanism 20(L), and a crankshaft 30.

[0194] The right mechanism 20(R) is a mechanism located on the right side of the fuselage 10, and the left mechanism 20(L) is a mechanism located on the left side of the fuselage 10. The right mechanism 20(R) and the left mechanism 20(L) may be located on the right or left side of the fuselage 10, or they may be embedded in each side of the fuselage 10. The elements constituting the right mechanism 20(R) and the left mechanism 20(L) are the same, and the same elements are given the same name and symbol. In addition, each element of the right mechanism 20(R) is marked with the symbols "(right)" and "(R)", and each element of the left mechanism 20(L) is marked with the symbols "(left)" and "(L)". In Figure 30, the elements shown by dashed lines are elements of the left mechanism 20(L) that are hidden by the right mechanism 20(R) or the fuselage 10.

[0195] The crankshaft 30 is rotatably inserted into a through-hole (not shown) provided in the body 10. The through-hole is a hole that penetrates the body 10 in a direction perpendicular to the plane of the paper in Figure 30.

[0196] Figure 31 is a schematic diagram in which the left mechanism 20(L) is omitted in order to explain the right mechanism 20(R). As shown in Figure 31, the right mechanism 20(R) includes a crank arm (right) 20-1(R), a first link (right) 20-2(R), and a second link (right) 20-3(R).

[0197] The crank arm (right) 20-1(R) may be straight, but may also be circular or elliptical, for example. The first link (right) 20-2(R) and the second link (right) 20-3(R) may be straight, but may be any shape, such as a bent shape or a curved shape. The first link (right) 20-2(R) and the second link (right) 20-3(R) may be formed from a single member, or may be constructed by connecting multiple members.

[0198] One end of the crank arm (right) 20-1(R) is fixedly connected to the crankshaft 30. The other end of the crank arm (right) 20-1(R) is rotatably connected to one end of the first link (right) 20-2(R) at the first connection point (right) C1(R). The other end of the first link (right) 20-2(R) is rotatably connected to one end of the second link (right) 20-3(R) at the second connection point (right) C2(R). The other end of the second link (right) 20-3(R) is rotatably connected to the fuselage 10 at the third connection point (right) C3(R). The third connection point (right) C3(R) is located in the fuselage 10 at a predetermined distance from the crankshaft 30.

[0199] As a configuration in which the crank arm (right) 20-1(R) and the first link (right) 20-2(R), the first link (right) 20-2(R) and the second link (right) 20-3(R), and the second link (right) 20-3(R) and the body 10 are connected so as to be rotatable with respect to each other, for example, holes may be provided in both members and the joint may be inserted into both holes, but any configuration that allows for rotatable connection may be adopted.

[0200] The first link (right) 20-2(R) includes the first link main part (right) 20-2A(R) and the leg part (right) 20-2B(R), which connect the crank arm (right) 20-1(R) and the second link (right) 20-3(R). The leg part (right) 20-2B(R) has a shape that mimics the leg (leg and foot) of a human or the like. However, while the leg of a human or the like rotates at the knee between the thigh and shin, there is no rotating configuration equivalent to the knee in the walking mechanism 1. The first link main part (right) 20-2A(R) and the leg part (right) 20-2B(R) are fixedly connected. In this embodiment, the first link main part (right) 20-2A(R) and the leg part (right) 20-2B(R) are fixedly connected at the first connection point (right) C1(R) and the second connection point (right) C2(R), but they may be connected at any point, or for example, at only one point. The first link main part (right) 20-2A(R) and the leg part (right) 20-2B(R) may be formed integrally, or they may be configured to be fixedly connected to multiple members.

[0201] The right mechanism 20(R) is configured such that when the leg (right) 20-2B(R) makes contact with the walking surface 100 (when it transitions from a state away from the walking surface 100 to a state in contact with the walking surface 100), the first connection point (right) C1(R), the crankshaft 30, and the second connection point (right) C2(R) are positioned in a straight line in that order. The lengths, connection positions, and angles of each component are configured accordingly. Figure 30 shows the walking mechanism 1 when the leg (left) 20-2B(L) makes contact with the walking surface 100, while Figure 32 shows the walking mechanism 1 when the leg (right) 20-2B(R) makes contact with the walking surface 100. Note that in Figure 32, the left mechanism 20(L) is omitted for explanatory purposes. As shown in Figure 32, when the leg (right) 20-2B(R) makes contact with the walking surface 100, the first connection point (right) C1(R), the crank shaft 30, and the second connection point (right) C2(R) are positioned in a straight line in this order. In Figure 32, the crank arm (right) 20-1(R) and the crank shaft 30 are hidden by the first link (right) 20-2(R) and are shown by dashed lines.

[0202] The connection angle between the first link main part (right) 20-2A(R) and the leg part (right) 20-2B(R) is configured such that when the leg part (right) 20-2B(R) makes contact with the walking surface 100, the acute angle (θ in Figure 32) formed by the line connecting the contact point of the leg part (right) 20-2B(R) and the second connection point (right) C2(R) and the line perpendicular to the walking surface 100 is less than 45 degrees. In this embodiment, θ is 30 degrees.

[0203] In this embodiment, the following configuration is adopted. The components that make up the right mechanism 20(R) are only the crank arm (right) 20-1(R), the first link (right) 20-2(R), and the second link (right) 20-3(R). Only the crank shaft 30 and the first link (right) 20-2(R) are connected to the crank arm (right) 20-1(R). The crank arm (right) 20-1(R) and the first link (right) 20-2(R) are connected only at the first connection point (right) C1(R), whether it is a direct connection or an indirect connection (a connection with another member in between). The first link (right) 20-2(R) and the second link (right) 20-3(R) are connected only at the second connection point (right) C2(R), regardless of whether the connection is direct or indirect (connected via another component in between). The only components that move in conjunction with the rotation of the crankshaft 30 are the crank arm (right) 20-1(R), the first link (right) 20-2(R), and the second link (right) 20-3(R).

[0204] As shown in Figure 31, the length from the axis center of the crankshaft 30 to the first connection point (right) C1(R) is called the effective length (right) CL(R) of the crank arm. The length of the line segment connecting the first connection point (right) C1(R) and the second connection point (right) C2(R) is called the effective length (right) L1(R) of the first link. The length of the line segment connecting the second connection point (right) C2(R) and the third connection point (right) C3(R) is called the effective length (right) L2(R) of the second link. The distance from the axis center of the crankshaft 30 to the third connection point (right) C3(R) is called the base distance (right) D(R). The straight line connecting the axis center of the crankshaft 30 and the third connection point (right) C3(R) is called the baseline (right) SL(R).

[0205] The sum of the effective length of the first link (right) L1(R) and the effective length of the second link (right) L2(R) is greater than or equal to the sum of the base distance (right) D(R) and the effective length of the crank arm (right) CL(R). The sum of the effective length of the first link (right) L1(R) and the effective length of the second link (right) L2(R) is greater than or equal to the sum of the base distance (right) D(R) and the effective length of the crank arm (right) CL(R). In other words, the following equation (1) is satisfied.

[0206] L1(R)+L2(R)≧D(R)+CL(R)...Equation (1)

[0207] This allows the crank arm (right) 20-1(R) to rotate 360 ​​degrees. Furthermore, if L1(R)+L2(R)>D(R)+CL(R), the second connection point (right) C2(R) can be prevented from moving beyond the baseline (right) SL(R) to the opposite side. A mechanism may also be provided to restrict the second connection point (right) C2(R) from moving beyond the baseline (right) SL(R) to the opposite side when L1(R)+L2(R)=D(R)+CL(R).

[0208] The absolute value of the difference between the effective length of the first link (right) L1(R) and the effective length of the second link (right) L2(R) is less than or equal to the absolute value of the difference between the base distance (right) D(R) and the effective length of the crank arm (right) CL(R). In other words, it satisfies equation (2) below.

[0209] |L1(R)-L2(R)|≦|D(R)-CL(R)|····Formula (2)

[0210] This allows the crank arm (right) 20-1(R) to rotate 360 ​​degrees. Furthermore, if |L1(R)-L2(R)|<|D(R)-CL(R)|, the second connection point (right) C2(R) can be prevented from moving beyond the baseline (right) SL(R) to the opposite side. In the case where |L1(R)-L2(R)|=|D(R)-CL(R)|, a mechanism may be provided to restrict the second connection point (right) C2(R) from moving beyond the baseline (right) SL(R) to the opposite side.

[0211] The base distance (right) D(R) is longer than the effective length of the crank arm (right) CL(R). This prevents the second connection point (right) C2(R) from moving to the opposite side beyond the baseline (right) SL(R).

[0212] The left mechanism 20(L) has the same configuration as the right mechanism 20(R) described above. The crank arm (right) 20-1(R) and the crank arm (left) 20-1(L) are fixedly connected to the crankshaft 30 with a phase difference of 180 degrees and are configured to extend in directions that are 180 degrees different. The position of the third connection point (left) C3(L) is the same as the position of the third connection point (right) C3(R) when viewed in the direction perpendicular to the plane of the paper in Figure 30.

[0213] The effective length of the crank arm (right) CL(R) and the effective length of the crank arm (left) CL(L) are the same length, the effective length of the first link (right) L1(R) and the effective length of the first link (left) L1(L) are the same length, and the effective length of the second link (right) L2(R) and the effective length of the second link (left) L2(L) are the same length. The base distance (right) D(R) and the base distance (left) D(L) are the same distance. The second connection point (right) C2(R) and the second connection point (left) C2(L) are configured to be on the same side with respect to the baseline SL(R) and SL(L) (which are the same straight line in this embodiment). In this embodiment, both the second connection point (right) C2(R) and the second connection point (left) C2(L) are located behind the baseline SL(R) and SL(L) (more conceptually, to the left with respect to the direction from the crank axis toward the third connection point). The second connection point (right) C2(R) and the second connection point (left) C2(L) may be positioned forward of the baseline SL(R) and SL(L) (more conceptually, to the right of the direction from the crank axis toward the third connection point). The second link (right) 20-3(R) and the second link (left) 20-3(L) are configured to be on the same side with respect to the baseline SL(R) and SL(L). The effective length of the crank arm (left) CL(L), the effective length of the first link (left) L1(L), the effective length of the second link (left) L2(L), the base distance (left) D(L), and the baseline SL(L) are shown in Figure 45.

[0214] Figures 33 to 45 are diagrams illustrating the operation of the walking mechanism 1. Figure 33 shows the walking mechanism 1 when the right leg 20-2B(R) is in contact with the walking surface 100, and just before the left leg 20-2B(L) leaves the walking surface 100.

[0215] In the walking mechanism 1 as shown in Figure 33, when the torso 10 is moved forward (to the right in Figure 33) by the user or the like, a force F1 shown in Figure 33 acts on the torso 10, and a force F2 shown in Figure 33 acts on the contact point of the leg (right) 20-2B(R). Figure 34 is a diagram in which the left mechanism 20(L) is omitted to make the movement of the right mechanism 20(R) at this time easier to understand. The following explanation will refer to Figure 34.

[0216] As described above, when the leg (right) 20-2B(R) makes contact with the walking surface 100, the angle of connection between the first link main part (right) 20-2A(R) and the leg (right) 20-2B(R) is configured such that the acute angle (θ in Figure 32) formed by the line connecting the contact point of the leg (right) 20-2B(R) and the second connection point (right) C2(R) and the line perpendicular to the walking surface 100 is less than 45 degrees. Therefore, when force F1 acts on the torso 10 and force F2 acts on the contact point, the leg (right) 20-2B(R) moves in a way that it slides under the torso 10.

[0217] Furthermore, the smaller the angle θ, the easier it becomes for the leg (right) 20-2B(R) to move under the torso 10. The angle θ may be adjusted by the force moving the torso 10 forward, the weight of the torso 10, etc. For example, if the torso 10 is heavy and / or the force moving the torso 10 forward is weak, the angle θ may be set to a smaller angle (e.g., 30 degrees).

[0218] In the state shown in Figure 34 (when the leg (right) 20-2B(R) is in contact with the walking surface 100), as described above using Figure 32, the first connection point (right) C1(R), the crank shaft 30, and the second connection point (right) C2(R) are located in a straight line in that order. In this state, the second connection point (right) C2(R) is difficult to move in the direction d1 toward the first connection point (right) C1(R). Also, the second connection point (right) C2(R) is difficult to move in the direction d2 toward the third connection point (right) C3(R). In other words, in the state shown in Figure 34, the second connection point (right) C2(R) is difficult to move in two directions (up and down and forward and backward).

[0219] As described above, when the leg (right) 20-2B(R) starts moving from the front, passing under the torso 10 and moving backward from the state shown in Figure 34, the second connection point (right) C2(R) is difficult to move in the vertical and forward / backward directions. Therefore, the first connection point (right) C1(R) rotates around the second connection point (right) C2(R) (the movement of D1 shown in Figure 34). As a result, the crank arm (right) 20-1(R) rotates to the right (clockwise) in Figure 34, allowing the crank shaft 30 to rotate in the correct direction (the rotational direction corresponding to the forward direction of the walking mechanism 1).

[0220] Furthermore, as the user continues to move the torso 10 forward (to the right in Figure 32), a force F1 shown in Figure 33 continues to act on the torso 10, causing the leg (right) 20-2B(R) to move from the front, through the underside of the torso 10, and backward. Accordingly, the walking mechanism 1 transitions in the order shown in Figures 33, 35, 36, 37, 38, 39, and 40. During this time, the leg (left) 20-2B(L) moves away from the walking surface 100 from backward to forward as the crankshaft 30 rotates.

[0221] Figure 40 shows the walking mechanism 1 when the leg (left) 20-2B(L), which was away from the walking surface 100, makes contact with the walking surface 100. In this state, if the torso 10 is further moved forward (to the right in Figure 40) by the user or the like, the leg (left) 20-2B(L) that has made contact with the surface begins to move backward from the front, passing below the torso 10, through the same action as described above using Figure 34, and the first connection point (left) C1(L) rotates around the second connection point (left) C2(L) (the movement corresponding to D1 shown in Figure 34). As a result, the crank arm (left) 20-1(L) rotates to the right in Figure 40, which allows the crank shaft 30 to rotate in the correct direction (the rotational direction corresponding to the forward direction of the walking mechanism 1).

[0222] After Figure 40, the user continues to move the torso 10 forward (to the right in Figure 40), resulting in the transitions in the order of Figures 41, 42, 43, 44, 45, and 33. During this time, the leg (right) 20-2B(R) moves away from the walking surface 100 from the rear to the front as the crankshaft 30 rotates.

[0223] As described above, the walking mechanism 1 can maintain walking motion by having the right leg 20-2B(R) and the left leg 20-2B(L) alternately make contact with the ground, and by the force that the contacting leg 20-2B receives from the walking surface 100, the crank shaft 30 is continuously rotated in the correct direction.

[0224] As is clear from Figure 32, the walking mechanism 1 is configured such that when the leg (right) 20-2B(R) is in contact with the ground and the first connection point (right) C1(R), the crankshaft 30, and the second connection point (right) C2(R) are in a straight line, the position of the third connection point (right) C3(R) is on the opposite side of the ground contact point of the leg (right) 20-2B(R) (i.e., above this straight line). With this configuration, when the first link (right) 20-2(R) slides under the torso 10, the first connection point (right) C1(R) moves in a clockwise arc around the crankshaft 30, and the second connection point (right) C2(R) also moves in a clockwise arc around the third connection point (right) C3(R). At this time, the directions of movement of the first connection point (right) C1(R) and the second connection point (right) C2(R) are almost opposite. More specifically, when the direction of movement of the first connection point (right) C1(R) is downward, the direction of movement of the second connection point (right) C2(R) is upward. Therefore, the first link (right) 20-2(R) rotates clockwise, and the leg (right) 20-2B(R) can move clockwise, like the movement of a human leg. The same applies to the left mechanism 20(L).

[0225] As shown in Figure 33, when the right leg 20-2B(R) and left leg 20-2B(L) of the walking mechanism 1 are in contact with the walking surface 100, the right crank arm 20-1(R) and left crank arm 20-1(L) are parallel to the walking surface 100. However, this is not a condition for the walking mechanism 1 to walk correctly. When the leg that is in front of the walking surface (right leg 20-2B(R) in Figure 33) makes contact with the surface, the first connection point, the crank axis, and the second connection point should be positioned in a straight line in that order, and the angle of the crank arm at that time is not a problem.

[0226] (Other variations) The shape of each component of the crank mechanism (for example, the support, crank arm, first link, and second link, etc.) is arbitrary and may be rod-shaped, plate-shaped, bent, curved, three-dimensional, such as a cone or column, or a combination of the aforementioned shapes.

[0227] The positions of the crankshaft and the third connection point on the support, the crankshaft and the first connection point on the crank arm, the first and second connection points on the first link, and the second and third connection points on the second link are arbitrary. For example, in Figure 1, the first connection point 31 and the second connection point 32 are provided at the end of the first link 34, but the first connection point 31 and the second connection point 32 may be provided at locations other than the end of the first link 34.

[0228] Each component of the crank mechanism and walking mechanism according to the embodiments described above may be manufactured integrally, or by combining multiple components, or a user may manufacture each component by combining multiple components and then manufacture the crank mechanism or walking mechanism. For example, the crank mechanism and walking mechanism may be distributed to the market as a whole or assembled, or they may be distributed to the market as an assembly kit for assembling the crank mechanism and walking mechanism. If distributed as an assembly kit, the package may contain instructions for assembling the crank mechanism and walking mechanism, or it may contain or include information on a website containing instructions or instructions on how to obtain an application for viewing instructions. For example, the package of an assembly kit for assembling crank mechanism 1 may include each component in the form of constituent elements such as the main body 21, crank shaft 22, crank arms 30, 40, first links 34, 44, and second links 35, 45. Alternatively, the assembly kit may include each component in the form of further separated members for assembling the constituent elements exemplified above. For example, the assembly kit package may include multiple rod-shaped parts for assembling the first links 34 and 44, and parts for connecting those parts. Also, for example, the parts for assembling the first links 34 and 44 may be used to assemble other components, such as the second links 35 and 45. In other words, the same parts may be used to assemble some of the components illustrated above. Furthermore, the parts for assembling each of the components illustrated above may be used to assemble devices different from the crank mechanism 1 and walking mechanism 10. In addition to the parts for assembling the crank mechanism and walking mechanism according to each embodiment, the assembly kit package may also contain parts for assembling parts attached to the crank mechanism 1 and walking mechanism 10, or parts for assembling other devices.

[0229] In the embodiment described above, the support 2 is provided with two mechanisms (specifically, the first mechanism 3 and the second mechanism 4) on both sides, but the support may be provided with three or more mechanisms (mechanisms corresponding to the first mechanism 3 and the second mechanism 4). For example, if four mechanisms are provided, mechanisms corresponding to the first mechanism 3 and the second mechanism 4 may be provided at one position on the support, and mechanisms corresponding to the first mechanism 3 and the second mechanism 4 may also be provided at other positions. Furthermore, three or more mechanisms may be provided on a single crankshaft.

[0230] In the embodiments described above, the walking mechanism is a mechanism that walks by grasping the torso, etc., with hands and moving it forward. However, the walking mechanism is not limited to a mechanism that is operated manually. For example, the walking mechanism may operate autonomously by a motor or the like. In this case, the walking mechanism may have, for example, a motor, and the legs rotate as a crankshaft, to which driving force is transmitted from the motor, rotates.

[0231] A link separate from the first and second links described above may be rotatably connected to the crank arm, and this link may be used to move the head, arms, etc., of the walking mechanism in conjunction with the rotation of the crank arm. However, such a component does not transmit forces from the walking surface to the crank arm.

[0232] In the above description, terms such as "torso," "right mechanism," "left mechanism," "crankshaft," "crank arm," "first link," "second link," "first connection point," "second connection point," "third connection point," "first link main part," "leg part," "effective length of crank arm," "effective length of first link," "effective length of second link," "base distance," and "baseline" are descriptions of each element in one embodiment and do not explain the terms used in the present invention.

[0233] Furthermore, by appropriately combining any of the embodiments and modifications described above, the respective effects can be achieved. [Explanation of Symbols]

[0234] 1 Crank mechanism 2 Support body 21 Main body 22 Crank shaft 3 First mechanism 30 Crank arm 31 First connection point 32 Second connection point 33 Third connection point 34 First link 341 Main portion 342 Leg portion 343 Connection portion 344 Ground contacting portion 345 Ground contacting surface 3451 Central portion 3452 Front end portion 3453 Rear end portion 3454 Inner portion 3455 Outer portion 35 Second link 4 Second mechanism 40 Crank arm 41 First connection point 42 Second connection point 43 Third connection point 44 First link 441 Main portion 442 Leg portion 443 Connection portion 444 Ground contacting portion 445 Ground contacting surface 4451 Central portion 4452 Front end portion 4453 Rear end portion 4454 Inner portion 4455 Outer portion 45 Second link

Claims

1. Torso and, A first mechanism is located on one side of the fuselage, A second mechanism located on the other side of the fuselage, The first mechanism and the second mechanism are connected by a crankshaft, Each of the first mechanism and the second mechanism is, A crank arm connected to the crankshaft and rotatable integrally with the crankshaft, A first link is connected to the crank arm so as to be rotatable around a first connection point, The first link is rotatably connected to the first link about a second connection point, and the second link is rotatably connected to the body about a third connection point, The crank arm of the first mechanism and the crank arm of the second mechanism are in phase with respect to the crank shaft, The second connection point of the first mechanism and the second connection point of the second mechanism are located on the same side with respect to the straight line connecting the crankshaft and the third connection point. Each of the first mechanism and the second mechanism satisfies the following conditions (1) and (2): L1+L2≧D+CL...Formula (1) |L1-L2|≦|D-CL|...Formula (2) [L1 is the effective length of the first link, which is the distance between the first connection point and the second connection point; L2 is the effective length of the second link, which is the distance between the third connection point and the second connection point; D is the distance between the crankshaft and the third connection point; and CL is the effective length of the crank arm, which is the distance between the crankshaft and the first connection point.] The first link of the first mechanism and the second mechanism each have a main part that connects the crank arm and the second link, and a leg that extends in a predetermined direction from a predetermined position of the main part and makes contact with the walking surface. The first link includes a shape that is bent by the main part and the leg part, The aforementioned bending is configured such that, when the leg makes contact with the walking surface, the angle formed by the direction from the second connection point toward the point of contact and a straight line perpendicular to the walking surface becomes less than 45 degrees. In each of the first mechanism and the second mechanism, A walking mechanism in which, when an external force is applied to the torso in a forward direction and the torso is moved forward, in each of the first and second mechanisms, a single first link receives a force that moves it backward relative to the torso due to the rearward force received from the walking surface by the leg portion that is in contact with the walking surface, and with its movement restricted by the second link at the second connection point, the first link rotates the crank arm at the first connection point, thereby causing the first and second mechanisms to alternately rotate the crank shaft.

2. The walking mechanism according to claim 1, wherein the leg portion of the first mechanism is configured to make contact with the walking surface after the state in which the first connection point, the crankshaft, and the second connection point are aligned in a straight line in that order has been exceeded, and the leg portion of the second mechanism is configured to make contact with the walking surface after the state in which the first connection point, the crankshaft, and the second connection point are aligned in a straight line in that order has been exceeded.

3. The walking mechanism according to claim 1 or 2, wherein the leg of the first mechanism is configured to make contact with the ground before the crankshaft, the first connection point, and the second connection point reach a state in which they are aligned in that order in the second mechanism, and the leg of the second mechanism is configured to make contact with the ground before the crankshaft, the first connection point, and the second connection point reach a state in which they are aligned in that order in the first mechanism.

4. The walking mechanism according to claim 1 or 2, wherein the leg portion of the first mechanism is configured to move away from the walking surface before the crankshaft, the first connection point, and the second connection point are aligned in that order in the first mechanism, and the leg portion of the second mechanism is configured to move away from the walking surface before the crankshaft, the first connection point, and the second connection point are aligned in that order in the second mechanism.

5. The walking mechanism according to claim 1 or 2, wherein the leg portion of the first mechanism is configured to move away from the walking surface after the state in which the first connection point, the crankshaft, and the second connection point are aligned in that order in the second mechanism, and the leg portion of the second mechanism is configured to move away from the walking surface after the state in which the first connection point, the crankshaft, and the second connection point are aligned in that order in the first mechanism.

6. The walking mechanism according to claim 1 or 2, wherein, in each of the first and second mechanisms, when the leg is subjected to a force from the walking surface, the rotational direction of the second connection point of the first link relating to the leg being subjected to the force, with respect to the third connection point, coincides with the rotational direction of the crankshaft.

7. The walking mechanism according to claim 1 or 2, wherein, for each of the first and second mechanisms, when the second connection point of one mechanism is furthest from the crankshaft, the second connection point of the other mechanism is configured to be on the opposite side of the line passing through the first connection point and the crankshaft from the third connection point.

8. The walking mechanism according to claim 1 or 2, wherein, for each of the first and second mechanisms, the position of the second connection point when it is closest to the crankshaft is located on the opposite side from the third connection point with respect to a straight line passing through the position of the second connection point when it is furthest from the crankshaft and the crankshaft.

9. The walking mechanism according to claim 1 or 2, wherein, for each of the first and second mechanisms, the effective length of the second link, which is the distance between the second connection point and the third connection point, is longer than the distance between the crankshaft and the third connection point.

10. The walking mechanism according to claim 1 or 2, wherein, for each of the first and second mechanisms, the member that transmits force from the walking surface and is rotatably connected to the crank arm is a single first link.

11. The walking mechanism according to claim 1 or 2, wherein, for each of the first mechanism and the second mechanism, the crank arm and the first link are connected only at the first connection point, whether directly or indirectly.

12. The walking mechanism according to claim 1 or 2, wherein, for each of the first and second mechanisms, the first link and the second link are connected only at the second connection point, whether directly or indirectly.

13. The walking mechanism according to claim 1 or 2, wherein, in each of the first and second mechanisms, there are no members other than the first link and the second link that move in conjunction with the rotation of the crankshaft.

14. The walking mechanism according to claim 1 or 2, wherein each of the first mechanism and the second mechanism consists only of the crank arm, a single first link, and a single second link.

15. The walking mechanism according to claim 1 or 2, wherein the crank arm of the first mechanism and the crank arm of the second mechanism are linear members extending in directions 180 degrees different from the crank axis.

16. Each of the first mechanism and the second mechanism satisfies the following conditions (1) and (2): L1+L2>D+CL...Formula (1) |L1-L2|<|D-CL|...Formula (2) [L1 is the effective length of the first link, which is the distance between the first connection point and the second connection point; L2 is the effective length of the second link, which is the distance between the third connection point and the second connection point; D is the distance between the crankshaft and the third connection point; and CL is the effective length of the crank arm, which is the distance between the crankshaft and the first connection point.] Furthermore, for each of the first mechanism and the second mechanism, the distance between the crank shaft and the third connection point is longer than the effective length of the crank arm, which is the distance between the crank shaft and the first connection point, according to claim 1 or 2.

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