Patent Grant
9161880
This invention relates to a walking assist device, more particularly to a walking assist device attached to the lower body of a user to assist his/her walk, which device can decrease protruding amounts of device knee joints of the device.
Recently known walking assist devices for assisting user's walk include, for instance, the one according to the technology set out in Patent Reference 1 below.
The walking assist device of the Patent Reference 1 is equipped with a support member capable of supporting the user and transmitting his/her body weight or load, shoe units capable of accommodating the user's feet, leg links having first links (thigh links) connected to the support member through joints corresponding to the hip joints to be swingable about a fulcrum and second links (shank links) connected to the shoe units and also connected to the first links through joints corresponding to the knee joints, and actuators connected to the first links and second links, and when the user is supported by the support member, the actuator is operated to displace the first links and second links relative to each other to produce assist forces that assist or bear at least part of the user's weight, thereby assisting the user's walk.
Patent Reference 1: Japanese Laid-Open Patent Application 2007-20909
In the walking assist device of the Patent Reference 1, the configuration as above has an advantage that, for instance, the difference in body height of the user can be absorbed by adjusting angles of the device joints corresponding to the knee joints, whilst having a disadvantage that since the device joints are protruded forward from the trunk of the user, an inertia force about the vertical axis is increased and also the appearance gives unnatural impression.
The object of this invention is therefore to overcome this problem by providing an walking assist device that can decrease forward protruding amounts of the device joints corresponding to the knee joints from the trunk of the user.
In order to achieve the object, according to one aspect, this invention is configured to have a walking assist device having a support member adapted to support a user and transmit user's body weight, a pair of leg links each connected to the support member through a first joint constituted of a swing mechanism to be swingable about a swing fulcrum and having a first link and a second link connected to the first link through a second joint, and actuators, each of the actuators being operated to displace the first link and the second link relative to each other to produce an assist force that assists at least part of the user's body weight so as to assist the user to walk, characterized in that: a forward protruding amount of the second joint to be protruded with change of an angle between the first link and the second link about the second joint is changed.
As recited in the walking assist device recited in claim 2 mentioned below, the device further includes a length reducing mechanism adapted to reduce length from the second joint to the swing fulcrum as the angle between the first link and the second link about the second joint is decreased, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link and the second link about the second joint is changed.
According to another aspect, the first joint includes an arc-shaped guide rail fastened to the support member and having its center of curvature at the swing fulcrum and a slider movably engaged with the guide rail, the leg link is connected to the support member to be swingable about the center of curvature of the guide rail, and the actuator is connected to a connecting rod interconnecting the first joint and the second link in the first link.
According to another aspect, the length reducing mechanism includes a slider gear fastened to the slider, a link gear meshed with the slider gear and connected to the actuator, and a rocker arm fastened at its one end with the link gear and rotatably connected at its other end to the connecting rod, and the link gear is driven by the actuator to rotate the rocker arm to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced.
According to another aspect, number of teeth of the slider gear is larger than that of the link gear.
According to another aspect, the length reducing mechanism includes one of components of a worm gear mechanism having a worm and a gear fastened to the slider and other thereof fastened to the connecting rod and also connected to the actuator, and the other is driven by the actuator to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced.
According to another aspect, the length reducing mechanism includes a guide formed on the slider and a second slider movably engaged with the guide and also fastened to the connecting rod, and the second slider is driven by the actuator to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced.
According to another aspect, the length reducing mechanism includes a link mechanism movably connecting the slider with the connecting rod, and the link mechanism is driven by the actuator to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced.
According to another aspect, the leg link includes a third link connected to the first joint, and the third link and the first link are interconnected by a third joint to be movable relative to each other, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link and the second link about the second joint is changed.
As recited in the walking assist device recited in claim 10 mentioned below, movement of the second joint describes trajectory having at least one inflection point as viewed from side when the actuator is operated to displace the first link and second link relative to each other.
According to another aspect, length from the second joint to the swing fulcrum is changed in line with trajectory having nonlinear characteristics as viewed from side as the angle between the first link and the second link about the second joint is decreased when the actuator is operated to displace the first link and second link relative to each other.
According to another aspect, the device further includes a fourth link connected to the first link and a fifth link connected at its one end to the fourth link and at other end to the third link, and a quadric-link mechanism constituted of the first, third, fourth and fifth links is driven by the actuator.
According to another aspect, the quadric-link mechanism establishes a dead point at which at least three of kinematic pair points are positioned in a straight line.
As recited in the walking assist device recited in claim 14 mentioned below, a drive force of the actuator is distributed to the first link and the second link to drive them.
According to another aspect, the second link is connected to a second quadric-link mechanism and the drive force of the actuator is distributed to the second link through the second quadric-link mechanism.
According to another aspect, the second link is connected to a chain mechanism and the drive force of the actuator is distributed to the second link through the chain mechanism.
According to another aspect, the second quadric-link mechanism shares at least one of kinematic pair points with the first quadric-link mechanism.
According to one aspect, it is configured to have a walking assist device having a support member adapted to support a user and transmit user's body weight, a pair of leg links each connected to the support member through a first joint constituted of a swing mechanism to be swingable about a swing fulcrum and having a first link and a second link connected to the first link through a second joint, and actuators, each of the actuators being operated to displace the first link and the second link relative to each other to produce an assist force that assists at least part of the user's body weight so as to assist the user to walk, characterized in that: a forward protruding amount of the second joint to be protruded with change of an angle between the first link and the second link about the second joint is changed. With this, where the second joint is corresponding to the knee joint, it becomes possible to change, i.e., decrease the forward protruding amount of the second joint to be protruded from the trunk of the user with change of the angle about the second joint, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance.
In claim 2, the device further includes a length reducing mechanism adapted to reduce length from the second joint to the swing fulcrum as the angle between the first link and the second link about the second joint is decreased, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link and the second link about the second joint is changed. With this, where the second joint is corresponding to the knee joint, since the forward protruding amount of the second joint from the trunk of the user is appropriately changed, it becomes possible to decrease the forward protruding amount of the second joint from the trunk of the user accordingly, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance.
According to another aspect, the first joint includes an arc-shaped guide rail fastened to the support member and having its center of curvature at the swing fulcrum and a slider movably engaged with the guide rail, the leg link is connected to the support member to be swingable about the center of curvature of the guide rail, and the actuator is connected to a connecting rod interconnecting the first joint and the second link in the first link. With this, in addition to the foregoing effects, it becomes possible to effectively absorb the difference in body height of the user by adjusting the angle of the second joint corresponding to the knee joint.
According to another aspect, the length reducing mechanism includes a slider gear fastened to the slider, a link gear meshed with the slider gear and connected to the actuator, and a rocker arm fastened at its one end with the link gear and rotatably connected at its other end to the connecting rod 46, and the link gear is driven by the actuator to rotate the rocker arm to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced. With this, in addition to the foregoing effects, the structure can be made simple.
According to another aspect, number of teeth of the slider gear is larger than that of the link gear. With this, in addition to the foregoing effects, it becomes possible to reduce speed to amplify torque and it can make the actuator compact.
According to another aspect, the length reducing mechanism includes one of components of a worm gear mechanism having a worm and a gear fastened to the slider and other thereof fastened to the connecting rod and also connected to the actuator, and the other is driven by the actuator to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced. With this, in addition to the foregoing effects, the forward protruding amount of the third joint from the trunk of the user can be decreased more smoothly.
According to another aspect, the length reducing mechanism includes a guide formed on the slider and a second slider movably engaged with the guide and also fastened to the connecting rod, and the second slider is driven by the actuator to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced. With this, in addition to the foregoing effects, since no gear is used, this configuration can decrease friction.
According to another aspect, the length reducing mechanism includes a link mechanism movably connecting the slider with the connecting rod, and the link mechanism is driven by the actuator to move the connecting rod backward such that the length from the second joint to the swing fulcrum is reduced. With this, in addition to the foregoing effects, since no gear is used, this configuration can decrease friction.
According to another aspect, the leg link includes a third link connected to the first joint, and the third link and the first link are interconnected by a third joint to be movable relative to each other, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link and the second link about the second joint is changed. With this, where the second joint is corresponding to the knee joint, when a positional relationship among the third link and other components is appropriately set, the length or distance from the swing fulcrum to the knee joint can be changed and hence, it becomes possible to decrease the forward protruding amount of the device knee joint from the trunk of the user, thereby decreasing the inertia force about the vertical axis, avoiding the interference with surrounding members and also mitigating the unnatural impression of the appearance.
Specifically, since the third link and first link are interconnected by the third joint to be movable relative to each other, when the third joint is driven, the length or distance from the swing fulcrum to the end of the leg link can be increased with increasing angle of the second joint. As a result, it becomes possible to ensure the large angle of the second joint at the time when the user stands upright and hence, the forward protruding amount of the device knee joint from the trunk of the user can be decreased.
In claim 10, movement of the second joint describes trajectory having at least one inflection point as viewed from side when the actuator is operated to displace the first link and second link relative to each other. With this, in addition to the foregoing effects, since the trajectory is appropriately set, the length or distance from the swing fulcrum to the end of the leg link can be increased with increasing angle of the second joint. As a result, it becomes possible to ensure the further large angle of the second joint at the time when the user stands upright.
According to another aspect, length from the second joint to the swing fulcrum is changed in line with trajectory having nonlinear characteristics as viewed from side as the angle between the first link and the second link about the second joint is decreased when the actuator is operated to displace the first link and second link relative to each other. With this, in addition to the foregoing effects, since the trajectory is appropriately set, similarly the length or distance from the swing fulcrum to the end of the leg link can be increased with increasing angle of the second joint. As a result, it becomes possible to ensure the further large angle of the second joint at the time when the user stands upright.
According to another aspect, the device further includes a fourth link connected to the first link and a fifth link connected at its one end to the fourth link and at other end to the third link, and a quadric-link mechanism constituted of the first, third, fourth and fifth links is driven by the actuator. With this, in addition to the foregoing effects, since the length of the links constituting the first quadric-link mechanism are appropriately set, it enables the input/output characteristics of the first quadric-link mechanism to exhibit the curve characteristics, thereby achieving the smooth movement of the leg link.
According to another aspect, the quadric-link mechanism establishes a dead point at which at least three of kinematic pair points are positioned in a straight line. With this, in addition to the foregoing effects, it becomes possible to more effectively decrease the forward protruding amount of the device knee joint of when (before/after) the user's knee is fully extended.
According to another aspect, a drive force of the actuator is distributed to the first link and the second link to drive them. With this, in addition to the foregoing effects, the installment of only one motor suffices, thereby achieving the simple and light structure.
According to another aspect, the second link is connected to a second quadric-link mechanism and the drive force of the actuator is distributed to the second link through the second quadric-link mechanism. With this, in addition to the foregoing effects, since the length of the links constituting the second quadric-link mechanism are appropriately set, it enables the input/output characteristics of the second quadric-link mechanism to exhibit the curve characteristics, thereby achieving the further smooth movement of the leg link.
According to another aspect, the second link is connected to a chain mechanism and the drive force of the actuator is distributed to the second link through the chain mechanism. With this, in addition to the foregoing effects, it is not necessary to take into account the intrinsic risk of the link mechanism like buckling, while the second link can be displaced relative to the first link more than 180 degrees, so that freedom of design can be enhanced.
According to another aspect, the second quadric-link mechanism shares at least one of kinematic pair points with the first quadric-link mechanism. With this, in addition to the foregoing effects, it becomes possible to make the structure simple due to the shared kinematic pair point.
Embodiments for carrying out a walking assist device according to the present invention will now be explained with reference to the attached drawings.
The explanation will be made with reference to
The left and right leg links 14 are made of aluminum. Each comprises a first link (thigh link) 22 connected to the support member 10 through a first joint 20 (corresponding to the human hip joint), a second link (shank link) 26 connected to the associated shoe unit 12 through a second joint 24 (corresponding to the human ankle joint), and a third joint 30 (corresponding to the human knee joint) interconnecting the first link 22 and second link 26.
The first link 22 and second link 26 of the leg link 14 are connected to the associated drive mechanism 16 which moves (drives) them relative to each other with the third joint 30, more precisely, a joint shaft 30a thereof as a fulcrum.
The support member 10 comprises a saddle-type seat 10a on which the user P can be seated astraddle, a support frame 10b located near the seat 10a to support it, and a back rest 10c rising from the support frame 10b to above the rear end (as viewed by the user P) of the seat 10a to contact the lower back of the user P. A grip 10d that can be grasped by the user P is attached to the back rest 10c.
The seat 10a is made of a cushioning material, and the support frame 10b and back rest 10c are made of materials of higher rigidity than the seat 10a.
A swing mechanism of the first joint 20 connecting the leg link 14 and support member 10 comprises an arc-shaped guide rail 32 fastened to the support member 10 and a slider 34 that engages with the guide rail 32 and is fixed to one end of the associated leg link 14. Although the guide rail 32 on the left side is only shown in
A plurality of rollers 36 are attached to each slider 34. The rollers 36 are fitted in a groove formed in the guide rail 32 to roll along the groove. Therefore, as indicated by an arrow in
In other words, each leg link 14 is configured such that it can swing about the center of curvature 32a (swing fulcrum (supporting point)) of the associated guide rail 32 in the longitudinal direction of the support member 10. Further, the guide rails 32 are pivotally supported on the back rest 10c of the support member 10 by a support shaft 38 installed to extend in the longitudinal direction of the support member 10 and hence, they can swing about the support shaft 38 in the lateral direction of the support member 10.
Thus the leg links 14 are configured such that they can swing forward and backward (in the traveling direction of the user P) about the centers of curvature 32a of the guide rails 32 as the swing fulcrums. Therefore, when the point of action of the upper body weight (load) of the user P relative to the support member 10 shifts forward of the swing fulcrum 32a to make the support member 10 descend forward, since the swing fulcrum 32a is located above the support member 10 in the direction of gravity, the point of action of the body weight is displaced rearward below the swing fulcrum 32a, thereby shortening the fore-aft distance between the swing fulcrum 32a and the point of action of the body weight to reduce rotational moment acting on the support member 10.
Then when the point of action of the body weight has moved as far as directly under the swing fulcrum 32a, the rotational moment acting on the support member 10 becomes zero and the support member 10 becomes stable. Thus, since the support member 10 converges on the stable state by itself, the support member 10 does not shift forward or backward at the location of the user P's crotch.
The guide rails 32 are enabled to swing sideways (relative to the traveling direction of the user P) about the swing fulcrum (support shaft) 38, so that the leg links 14 can swing sideways to make it possible for the user P to swing the legs outward at will.
Each of the shoe units 12 comprises a shoe 12a to be worn on a foot of the user P, an L-shaped (as viewed from the front looking rearward along the path of user P travel) connecting member 12b made of carbon material and installed in the shoe 12a for enabling the corresponding foot of the user P to rest thereon, and an insole 12c of urethane rubber or similar rubbery elastic material that lies on the upper surface of the connecting member 12b. The second link 26 of each leg link 14 is connected to the associated connecting member 12b through the associated second joint 24 of triaxial structure.
The drive mechanism 16 comprises an actuator (electric motor) 40 located near an end of the first link 22, an output shaft 40b outputting the rotation of the actuator 40 reduced in speed through a speed reducer 40a (shown in
More specifically, the first link 22 having a hollow structure accommodates the connecting rod 46 therein. The connecting rod 46 is attached at its one end to the rocker arm 42 by a pivot 46a and at the other end to the driven crank arm 44 by a pivot 46b, thereby establishing rotatable connections.
As shown in
The walking assist control for assisting the user P's walk will be explained next.
As shown in
The outputs of the sensors 60 and 62 are sent to a controller 64 housed in the support frame 10b of the support member 10. The controller 64 comprises a microcomputer equipped with a CPU, ROM, RAM and input-output (I/O) ports, and executes assist control for producing assist forces that assist the user P's walk.
More specifically, the controller 64 multiplies the value of the assist forces set in advance by a proportion of the total load acting on the feet of the user P that is borne by the individual feet calculated from the outputs of the force sensors 60, and defines the obtained products as desired values of the assist forces to be produced in the respective leg links 14. For example, where the load (weight) of the device D is 60 (N) and the assist force is 30 (N), the set value will be 90 (N).
Each assist force acts along the line in
More specifically, when the user P is supported as seated on the seat 10a of the support member 10, the controller 64 operates the actuators 40 of the drive mechanisms 16 to produce relative movement between the first links 22 and the second links 26 of the leg links 14 about the joint shafts 30a of the third joints 30 through the connecting rods 46, thereby helping the user P walk by producing supporting forces, i.e., assist forces, to support at least part of the user P's body weight.
The assist forces produced in the leg links 14 are transmitted through the support member 10 to the trunk of the user P to assist his/her walking by reducing the load acting on the legs of the user P. The user P is presumed to be a worker at a factory or the like who works in a standing posture.
Thus the walking assist device D is configured to include the support member 10 capable of supporting the user P to transmit the user's body weight or load, the leg links 14 connected to the support member 10 to be swingable about the swing fulcrum 32a through the first joints 20 constituted as the swing mechanism and having the first links 22 and the second links 26 connected to the first links 22 through the third joints (second joints) 30, and the electric motors (actuator) 40, wherein the motors 40 are operated to displace the first and second links 22, 26 relative to each other to produce assist forces that assist or bear at least part of the user's weight, thereby assisting the user's walk. The details of the operation of the device D is described in the Patent Reference 1 and the further explanation will not be made.
The walking assist device D according to the embodiments is characterized by length reducing mechanisms 70 each of which reduces length or distance from the third joint 30 (more precisely, the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) as an angle (hereinafter called “knee angle”) between the first and second links 22, 26 about the third joint 30 is decreased.
The explanation thereof will be made.
As illustrated, each length reducing mechanism 70 comprises a slider gear 70a fastened to the slider 34, a link gear 70b meshed with the slider gear 70a and connected to the actuator 40, and the rocker arm 42. One end of the rocker arm 42 is fastened with the link gear 70b and the other end thereof is rotatably connected to the connecting rod 46.
The slider gear 70a comprising a sector gear is attached to two triangular plates 70a1 fastened to the slider 34 by bolts, i.e., is fastened to the slider 34 through the plates 70a1. The link gear 70b is fastened (or connected) to the actuator 40, i.e., the output shaft 40b thereof, as shown in
The operation of the mechanism 70 will be explained with reference to
As mentioned in the foregoing, the device D is configured so that the third joint 30 is protruded forward from the trunk of the user P to absorb the difference in body height of the user P. As a result, the inertia force about the vertical axis is increased and also the appearance gives the unnatural impression.
To cope with it, in this embodiment, there is provided the length reducing mechanism 70 for reducing the length or distance from the third joint 30 to the swing fulcrum (center of curvature 32a) and the link gear 70b is driven by the actuator 40 to rotate the rocker arm 42 so as to move the connecting rod 46 backward as shown in
Consequently, as shown in
Specifically, the link gear 70b is driven by the actuator 40 to rotate the rocker arm 42 to move the connecting rod 46 backward, whereby the first joint 20 is moved backward in the traveling direction of the user, in other words, the length of the first link 22 is virtually reduced with decreasing device knee angle, as shown in
Owing to this configuration, as shown in
As stated above, this embodiment is configured to have a walking assist device D having a support member 10 adapted to support a user P and transmit user's body weight, a pair of leg links 14 each connected to the support member 10 through a first joint 20 constituted of a swing mechanism to be swingable about a swing fulcrum (center of curvature 32a) and having a first link 22 and a second link 26 connected to the first link 22 through a second joint (third joint 30), and actuators 40, each of the actuators being operated to displace the first link 22 and the second link 26 relative to each other to produce an assist force that assists at least part of the user P's body weight so as to assist the user P to walk, characterized in that: a forward protruding amount of the second joint (third joint 30) to be protruded with change of an angle between the first link 22 and the second link 26 about the second joint (third joint 30) is changed. With this, where the second joint (third joint 30) is corresponding to the knee joint, it becomes possible to change, i.e., decrease the forward protruding amount of the second joint to be protruded from the trunk of the user with change of the angle about the second joint, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance.
More specifically, the device further includes a length reducing mechanism 70 adapted to reduce length from the second joint (third joint 30, more precisely the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) as the angle between the first link 22 and the second link 26 about the second joint (third joint 30) is decreased, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link 22 and the second link 26 about the second joint is changed. With this, where the second joint (third joint 30) is corresponding to the knee joint, since the forward protruding amount of the second joint (third joint 30) from the trunk of the user is appropriately changed, it becomes possible to decrease the forward protruding amount of the joint 30 from the trunk of the user P accordingly, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance.
Further, the first joint 20 includes an arc-shaped guide rail 32 fastened to the support member 10 and having its center of curvature 32a at the swing fulcrum and a slider 34 movably engaged with the guide rail 32, the leg link 14 is connected to the support member 10 to be swingable about the center of curvature 32a of the guide rail 32, and the actuator 40 is connected to a connecting rod 46 interconnecting the first joint 20 and the second link 26 in the first link 22. With this, in addition to the foregoing effects, it becomes possible to effectively absorb the difference in body height of the user P by adjusting the angle of the third joint 30 corresponding to the knee joint.
Further, the length reducing mechanism 70 includes a slider gear 70a fastened to the slider 34, a link gear 70b meshed with the slider gear 70a and connected to the actuator 40, and a rocker arm 42 fastened at its one end with the link gear 70b and rotatably connected at its other end to the connecting rod 46, and the link gear 70b is driven by the actuator 40 to rotate the rocker arm 42 to move the connecting rod 46 backward (the length of the first link 22 is virtually reduced) such that the length d from the third joint 30 to the swing fulcrum is reduced. With this, in addition to the foregoing effects, the structure can be made simple.
Further, number of teeth of the slider gear 70a is larger than that of the link gear 70b. With this, in addition to the foregoing effects, it becomes possible to reduce speed to amplify torque and it can make the actuator 40 compact.
As illustrated, in the second embodiment, the output shaft 40b of the actuator 40 of each drive mechanism 16 is installed parallel with the axial direction of the connecting rod 46. The actuator 40 comprises the electric motor the same as in the first embodiment.
The explanation will be made with reference to
As shown in
The ball screw mechanism 74 is equipped with a cylindrical nut member 74a fitted over the linear motion shaft 72 to be coaxial and a plurality of balls 74b held on the inner periphery of the nut member 74a to be engaged with the groove 72a. When the nut member 74a is rotated about the linear motion shaft 72, the balls 74b are displaced along the groove 72a so that the linear motion shaft 72 is moved in the axial direction relative to the nut member 74a.
One end of the nut member 74a is fastened with a cylindrical member 82 fitted over the linear motion shaft 72 to be coaxial with the nut member 74a. The cylindrical member 82 is housed in the case 76, having clearance between the linear motion shaft 72 and itself. The nut member 74a and cylindrical member 82 are supported by the case 76 to be rotated about the linear motion shaft 72 integrally with each other.
The output shaft 40b of each actuator 40 is fastened with a drive pulley 84a of the aforementioned belt pulley mechanism 84 and the cylindrical member 82 is fastened with a driven pulley 84b. The pulleys 84a, 84b are interconnected by a belt 84c extending through a notch formed on the side case 76b.
Owing to the above configuration, the rotational drive force outputted from the output shaft 40b of the actuator 40 is transmitted to the cylindrical member 82 through the belt pulley mechanism 84, so that the cylindrical member 82 and nut member 74a are integrally rotated and it displaces the linear motion shaft 72 in the axial direction.
Specifically, the rotational drive force of the actuator 40 is transformed to the translational force in the axial direction of the linear motion shaft 72 through the belt pulley mechanism 84 and ball screw mechanism 74 and the linear motion shaft 72 displaces the connecting rod 46 in the axial direction.
Based on the above premise, the explanation of
The output shaft 40b of the actuator 40 is extended on the end side of the drive pulley 84a of the belt pulley mechanism 84 and the outer surface of the output shaft 40b is formed with the worm 86a, i.e., the other of the components of the worm gear mechanism 86, to be meshed with the gear 86b. The worm 86a is attached to the main case 76a, i.e., the base end of the connecting rod 46, through a stay 86a1. The remaining configuration is the same as that in the first embodiment.
In the above configuration, when the actuator 40 is operated to rotate the output shaft 40b thereof through the speed reducer 40a, the worm 86a is moved backward and the base end of the connecting rod 46 is moved backward accordingly, as shown in
Specifically, as shown in
As stated above, in the second embodiment, the length reducing mechanism 70 includes one of components of a worm gear mechanism 86 having a worm 86a and a gear 86b fastened to the slider 34 and other thereof fastened to the connecting rod 46 and also connected to the actuator 40, and the other is driven by the actuator 40 to move the connecting rod 46 backward such that the length d from the third joint 30 to the swing fulcrum is reduced. With this, where the third joint 30 is corresponding to the knee joint, it becomes possible to decrease the forward protruding amount of the joint 30 from the trunk of the user P accordingly, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance. Further, the forward protruding amount of the third joint from the trunk of the user can be decreased more smoothly.
The walking assist device D according to the third embodiment is an alternate example of that of the second embodiment, in which instead of the worm gear mechanism, a guide and second slider are provided. Specifically, as shown in
The second slider 92 is movably engaged with the guide 90 and includes a triangular second slider 92a and plate-shaped second slider 92b.
One component of the second slider 92, i.e., second slider 92a has a pin 92a1 projecting therefrom and the other component, i.e., the second slider 92b has a slot 92b1 bored therein. The pin 92a1 of the one second slider 92a is inserted in the slot 90a and the slot 92b1 of the other second slider 92b is inserted with the pin of the guide 90b, so that the second slider 92 is movably engaged with the guides 90a, 90b.
The one second slider 92a is attached to the main case 76a, i.e., the base end of the connecting rod 46, while the other second slider 92b is fixed to the connecting rod 46 at the middle thereof. The remaining configuration is the same as that in the first embodiment.
In the above configuration, when the actuator 40 is operated and the output shaft 40b thereof is rotated, the one second slider 92a is moved backward. Specifically, as is clear from a comparison of
The other second slider 92b is provided for guiding the lateral movement of the one second slider 92a relative to the guide 90a and hence, is not moved back and forth in response to the operation of the actuator 90.
As stated above, in the third embodiment, the length reducing mechanism 70 includes a guide 90 formed on the slider 34 and a second slider 92a, 92b movably engaged with the guide 90 and also fastened to the connecting rod 46, and the second slider 92a, 92b is driven by the actuator 40 to move the connecting rod 46 backward such that the length d from the third joint (more precisely the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) is reduced. With this, where the third joint 30 is corresponding to the knee joint, it becomes possible to decrease the forward protruding amount of the joint 30 from the trunk of the user P accordingly, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance. Further, since no gear is used, this configuration can decrease friction.
The walking assist device D according to the fourth embodiment is an alternate example of that of the third embodiment, in which instead of the second slider, a link mechanism is provided. Specifically, as shown in
The other end of the third link 94a is attached to the main case 76a, i.e., the base end of the connecting rod 46, while the fourth link 94b is fixed to the connecting rod 46 at the middle thereof. The remaining configuration is the same as that in the first embodiment.
In the above configuration, the link mechanism 94 movably interconnects the slider 34 and connecting rod 46. Consequently, when the actuator 40 is operated and the output shaft 40b thereof is rotated, the connecting rod 46 is moved backward relative to the slider 34 through the link mechanism 94.
Specifically, as shown in
As stated above, in the fourth embodiment, the length reducing mechanism 70 includes a link mechanism 94 movably connecting the slider 34 with the connecting rod 46, and the link mechanism 94 is driven by the actuator 40 to move the connecting rod 46 backward such that the length d from the third joint 30 (more precisely the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) is reduced. With this, where the third joint 30 is corresponding to the knee joint, it becomes possible to decrease the forward protruding amount of the joint 30 from the trunk of the user P accordingly, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance. Further, since no gear is used, this configuration can decrease friction.
Note that
As shown in
More specifically, the third link 100 is equipped with a link member 100a fastened to the slider (movable member) 34 to be engaged with the guide rail 32 that is a constituent element of the swing mechanism of the first joint 20, and with a rocker arm 100b fastened to the link member 100a through the fourth joint 102.
The fourth joint 102 is provided with a ball bearing 102a and the third link 100 is connected to the first link 22 to be rotatable through the ball bearing 102a. The first link 22 is installed with a bell crank 104 in the vicinity of the fourth joint 102, etc. The output shaft of the electric motor (actuator) 40 constituting the drive mechanism 16 is positioned near the bell crank 104. The bell crank 104 is supported by the ball bearing 104a.
The output of the motor 40 is transmitted to the bell crank 104 to rotate or swing the bell crank 104 about its rotary shaft 104b. One end of the rocker arm 100b and one crank (fourth link) 104c of the bell crank 104 are rotatably interconnected by a connecting rod (fifth link) 106.
Similarly to the first embodiment, the first link 22 is installed with the connecting rod 46 that extends over the substantially entire length of the first link 22 and reaches near the third joint 30. The second link 26 connected to the third joint 30 through the ball bearing 30a to be rotatable (movable) relative to the first link 22, is formed with a driven crank arm 44.
The other crank 104d of the bell crank 104 having a function of a drive crank arm is connected to the driven crank arm 44 through the connecting rod 46 to transmit the output of the motor 40 to the driven crank arm 44, so that the second link 26 is displaced relative to the first link 22 about the third joint 30 as a fulcrum.
Thus the leg link 14 constituted of the first link 22 and second link 26 comprises a first quadric-link mechanism 110 having the rocker arm 100b, the connecting rod 106, the one crank 104c of the bell crank 104, and the link connecting the rotary shaft 104b of the bell crank 104 with a joint shaft of the fourth joint 102, i.e., the first link 22.
Further, the leg link 14 comprises, in the vicinity of the first quadric-link mechanism 110, a second quadric-link mechanism 112 having the other crank 104d of the bell crank 104, the connecting rod 46, the link connecting the third joint 30 with the rotary shaft 104b of the bell crank 104 (i.e., first link 22), and the driven crank arm 44 (i.e., second link 26).
As illustrated, the first quadric-link mechanism 110 and second quadric-link mechanism 112 are configured to share the rotary shaft 104b of the bell crank 104, i.e., at least one of kinematic pair points constituting the mechanisms 110, 112.
Next, the operation of the leg link 14 is explained with reference to
In
When the motor 40 is rotated reversely under this condition, the bell crank 104 is rotated clockwise about the rotary shaft 104b in
Specifically, the first quadric-link mechanism 110 is configured so that a rotary shaft 100b1 of the rocker arm 100b, a rotary shaft 104c1 of the one crank 104c of the bell crank, and a rotary shaft 104d1 of the other crank 104d of the bell crank 104 are positioned in a straight line, in other words, so that at least the three kinematic pair points are positioned in a straight line, i.e., configured to have the dead point.
Then, when the motor 40 is further rotated in the same direction, the three rotary shafts 100b1, 104c1, 104d1 are moved to pass the dead point and further moved to allow the user P's knee to bend to the maximum extent, as shown in
Further, since the first quadric-link mechanism 110 and second quadric-link mechanism 112 are configured to share the rotary shaft (kinematic pair point) 104b of the bell crank 104, the movement of the first quadric-link mechanism 110 is transmitted to the second quadric-link mechanism 112 through the rotary shaft 104b.
Thus, in the fifth embodiment, the drive force of the motor 40 is distributed to the first and second links 22, 26 to drive them, and the second link 26 is connected with the second quadric-link mechanism 112 (that shares the rotary shaft with the first quadric-link mechanism 110) so that the drive force of the motor 40 is distributed (transmitted) to the second link 26 through the second quadric-link mechanism 112.
More specifically, the movement of the crank 104d functioning as the drive crank arm of the bell crank 104 is transmitted to the driven crank arm 44 through the connecting rod 46, so that the second link 26 is moved relative to the first link 22 about the axis line of the third joint (knee joint) 30.
Further, in the fifth embodiment, when the second link 26 is moved relative to the first link 22 about the axis line of the third joint (knee joint) 30, as shown in
Furthermore, as the angle between the first and second links 22, 26 about the third joint 30, i.e., the knee joint angle is decreased, as shown in
As stated above, in the fifth embodiment, the leg link 14 includes a third link 100 connected to the first joint 20, and the third link 100 and the first link 22 are interconnected by a fourth joint (third joint) 102 to be movable relative to each other, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link 22 and the second link 26 about the second joint (third joint) 30 is changed. With this, where the third joint (second joint) 30 is corresponding to the knee joint, when a positional relationship among the third link 100 and other components is appropriately set, the length or distance from the swing fulcrum 32a to the knee joint can be changed and hence, it becomes possible to decrease the forward protruding amount of the knee joint (third joint 30) from the trunk of the user P, thereby decreasing the inertia force about the vertical axis, avoiding the interference with surrounding members and also mitigating the unnatural impression of the appearance.
Specifically, since the third link 100 and first link 22 are interconnected by the fourth joint (third joint) 102 to be movable relative to each other, when the fourth joint 102 is driven, the length or distance from the swing fulcrum 32a to the end of the leg link 14 (shoe unit 12) can be increased with increasing angle (knee joint angle) of the third joint (second joint) 30. As a result, it becomes possible to ensure the large angle (knee joint angle) of the third joint 30 at the time when the user P stands upright and hence, the forward protruding amount of the device knee joint from the trunk of the user P can be decreased.
Further, movement of the third joint (second joint) 30 describes trajectory having at least one inflection point Pi as viewed from side when the motor 40 is operated to displace the first link 22 and second link 26 relative to each other. With this, in addition to the foregoing effects, since the trajectory is appropriately set, the length or distance from the swing fulcrum 32a to the end of the leg link 14 can be increased with increasing angle of the third joint (second joint) 30. As a result, it becomes possible to ensure the further large angle of the third joint 30 at the time when the user P stands upright.
Further length from the third joint 30 to the swing fulcrum 32a is changed in line with trajectory having nonlinear characteristics as viewed from side as the angle between the first link 22 and the second link 26 about the third joint (second joint) 30 is decreased when the motor 40 is operated to displace the first link 22 and second link 26 relative to each other. With this, in addition to the foregoing effects, since the trajectory is appropriately set, similarly the length or distance from the swing fulcrum 32a to the end of the leg link 14 can be increased with increasing angle of the third joint 30. As a result, it becomes possible to ensure the further large angle of the third joint 30 at the time when the user P stands upright.
Further, the device further includes one crank 104c of the bell crank 104 (fourth link) connected to the first link 22 and a connecting rod (fifth link) 106 connected at its one end to the one crank 104c and at other end to the third link 100, i.e., the rocker arm 100b thereof, and a first quadric-link mechanism 110 constituted of the first link 22, third link 100, crank 104c and connecting rod 106 is driven by the motor (actuator) 40. With this, in addition to the foregoing effects, since the length of the links constituting the first quadric-link mechanism 110 are appropriately set, it enables the input/output characteristics of the first quadric-link mechanism 110 to exhibit the curve characteristics, thereby achieving the smooth movement of the leg link 14.
Further, the first quadric-link mechanism 110 establishes a dead point at which at least three of kinematic pair points are positioned in a straight line. With this, in addition to the foregoing effects, it becomes possible to more effectively decrease the forward protruding amount of the device knee joint of when (before/after) the user P's knee is fully extended.
Further, a drive force of the motor (actuator) 40 is distributed to the first link 22 and the second link 26 to drive them. With this, in addition to the foregoing effects, the installment of only one motor 40 suffices, thereby achieving the simple and light structure.
Further, the second link 26 is connected to a second quadric-link mechanism 112 and the drive force of the motor 40 is distributed to the second link 26 through the second quadric-link mechanism 112. With this, in addition to the foregoing effects, since the length of the links constituting the second quadric-link mechanism 112 are appropriately set, it enables the input/output characteristics of the second quadric-link mechanism 112 to exhibit the curve characteristics, thereby achieving the further smooth movement of the leg link 14.
Further, the second quadric-link mechanism 112 shares at least one of kinematic pair points with the first quadric-link mechanism 110. With this, in addition to the foregoing effects, it becomes possible to make the structure simple due to the shared kinematic pair point.
The explanation will be made with focus on points of difference from the fifth embodiment. In the sixth embodiment, as shown in
Specifically, the third link 200 has a portion fixed to the slider 34 in engagement with the guide rail 32 constituting the swing mechanism of the first joint 20, while including a link member 200a of a wide plate shape spreading over an upper end of the first link 22, and a rocker arm 200b connected to the link member 200a through the fourth joint 202. The first link 22 is formed tapered in a region overlapping the third link 200, and one end of the rocker arm 200b is connected to the first link 22.
More specifically, the one end of the rocker arm 200b is rotatably connected to the link member 200a through the fourth joint 202 and a rotary shaft 200b1 of the other end thereof is disposed with a ball bearing so that the rocker arm 200b is rotatably connected to the first link 22 at a position on the base end side of the tapered portion through the ball bearing.
A crank 204 is rotatably connected to the first link 22 at a position on the tip side of the tapered portion. In other words, the tapered portion of the first link 22 functions as a connecting rod 206. The crank 204 installed on the tip side of the first link 22 is connected to the connecting rod 206 through a rotary shaft 204a having a ball bearing.
The other end of the crank 204 is connected to the output shaft of the motor 40 through a rotary shaft 204b having a ball bearing, so that the output of the motor 40 is transmitted to the crank 204 to swing the crank 204 about the rotary shaft 204b.
The movement of the crank 204 is transferred through the connecting rod 206 to the rocker arm 200b to swing it. Specifically, the crank 204 and rocker arm 200b constitute a parallel link and hence, are swung in parallel in response to the output of the motor 40, thereby moving the first link 22 in the swing direction.
The rocker arm 200b is disposed in the vicinity of the fourth joint 202 with a rotary shaft 200b2 where one end of the connecting rod 46 is rotatably connected. The connecting rod 46 extends over the substantially entire length of the first link 22 and is connected to the driven crank arm 44 of the third joint 30.
As a result, the output of the motor 40 is transmitted to the driven crank arm 44 through the crank 204, rocker arm 200b and connecting rod 46, so that the second link 26 is displaced relative to the first link 22 about the third joint 30 as a fulcrum.
Thus, in the sixth embodiment, the leg link 14 having the first and second links 22, 26 comprises a first quadric-link mechanism 210 constituted of the rocker arm 200b, connecting rod 206, crank 204 and link connecting the rotary shaft 240b of the crank 204 with the fourth joint 202, i.e., first link 22.
Further, the leg link 14 comprises, in the vicinity of the first quadric-link mechanism 210, a second quadric-link mechanism 212 constituted of the rocker arm 200b, more precisely the rocker arm 200b including an axis line interconnecting rotary shafts 200b1 and 200b2, the connecting rod 46, the link connecting the third joint 30 with the rotary shaft 200b1 of the rocker arm 200b (and connecting rod 206) (i.e., the first link 22), and the driven crank arm 44 (i.e., the second link 26).
As illustrated, the first quadric-link mechanism 210 and second quadric-link mechanism 212 are configured to share the rotary shaft 200b1 of the rocker arm 200b (and connecting rod 206), i.e., at least one of kinematic pair points constituting the quadric-link mechanisms 210 and 212.
Next, the operation of the aforementioned leg link 14 is explained with reference to
Since the position of the crank 204 in
When the rotation of the crank 204 reaches a certain angle or thereabout as shown in
Then, when the motor 40 is further rotated in the same direction, the three rotary shafts 200b1, 204a, 204b are moved to pass the dead point and further moved to allow the user P's knee to bend to the maximum extent, as shown in
Further, since the first quadric-link mechanism 210 and second quadric-link mechanism 212 are configured to share the rotary shaft (kinematic pair point) 200b1 of the rocker arm 200b (and connecting rod 206), the movement of the first quadric-link mechanism 210 is transmitted to the second quadric-link mechanism 212 through the rotary shaft 200b1.
Thus, in the sixth embodiment, the drive force of the motor 40 is distributed to the first and second links 22, 26 to drive them, and the second link 26 is connected with the second quadric-link mechanism 212 (that shares the rotary shaft with the first quadric-link mechanism 210) so that the drive force of the motor 40 is distributed (transmitted) to the second link 26 through the first and second quadric-link mechanisms 210, 212.
Further, in the sixth embodiment, when the second link 26 is moved relative to the first link 22 about the axis line of the third joint (knee joint) 30, as shown in
In the sixth embodiment, the first and second quadric-link mechanisms 210, 212 have the same structures as in the fifth embodiment.
As stated above, in the sixth embodiment, the leg link 14 includes a third link 200 having the swing mechanism and connected to the first joint 20, and the third link 200 and the first link 22 are interconnected by a fourth joint (third joint) 202 to be movable relative to each other, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link 22 and the second link 26 about the second joint (third joint 30) is changed. With this, where the third joint (second joint) 30 is corresponding to the knee joint, it becomes possible to change the length or distance from the swing fulcrum 32a to the knee joint. Therefore, the forward protruding amount of the device knee joint from the trunk of the user P can be decreased, thereby decreasing the inertia force about the vertical axis, avoiding the interference with surrounding members and also mitigating the unnatural impression of the appearance. The remaining configuration is the same as that in the fifth embodiment.
The explanation will be made with focus on points of difference from the foregoing embodiments. In the seventh embodiment, as indicated by an imaginary line in the drawing, instead of the second quadric-link mechanism 112 (or 212), a chain mechanism 120 is provided. The chain mechanism 120 is wound around the bell crank 104 and third joint 30 through an idler 122.
Specifically, in the seventh embodiment, the drive force of the motor 40 is distributed to the first and second links 22, 26 to drive them, and the second link 26 is connected with the chain mechanism 120 so that the drive force of the motor 40 is distributed (transmitted) to the second link 26 through the first quadric-link mechanism 110 (or 210) and chain mechanism 120. The remaining configuration is the same as that in the fifth embodiment.
As stated above, the seventh embodiment is configured to the second link 26 is connected to a chain mechanism 120 and the drive force of the motor 40 is distributed to the second link 26 through the chain mechanism 120. With this, in addition to the foregoing effects, it is not necessary to take into account the intrinsic risk of the link mechanism like buckling, while the second link 26 can be displaced relative to the first link 22 more than 180 degrees, so that freedom of design can be enhanced. The remaining configuration is the same as that in the fifth and sixth embodiments.
Note that, in the fifth and sixth embodiments, the length of the links constituting the first and second quadric-link mechanisms 110, 210, 112, 212 may be suitably changed. For instance,
As mentioned in the foregoing, in the first to fourth embodiments, it is configured to have a walking assist device D having a support member (load transmitting member) 10 adapted to support a user P and transmit user's body weight, a pair of leg links 14 each connected to the support member 10 through a first joint 20 constituted of a swing mechanism to be swingable about a swing fulcrum 32a and having a first link 22 and a second link 26 connected to the first link 22 through a second joint (third joint 30), and actuators (electric motor) 40, each of the actuators 40 being operated to displace the first link 22 and the second link 26 relative to each other to produce an assist force that assists at least part of the user P's body weight so as to assist the user P to walk, characterized in that: a forward protruding amount of the second joint (third joint 30) to be protruded with change of an angle between the first link 22 and the second link 26 about the second joint (third joint 30) is changed.
Specifically, the device further includes a length reducing mechanism 70 adapted to reduce length d from the second joint (third joint 30, more precisely the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) as the angle between the first link 22 and the second link 26 about the second joint (third joint 30) is decreased.
More specifically, the device further includes the length reducing mechanism 70 adapted to reduce the length d from the second joint (third joint 30, more precisely the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) as the angle between the first link 22 and the second link 26 about the second joint (third joint 30) is decreased, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link 22 and the second link 26 about the second joint is changed.
Further, the first joint 20 includes an arc-shaped guide rail 32 fastened to the support member 10 and having its center of curvature 32a at the swing fulcrum and a slider 34 movably engaged with the guide rail 32, the leg link 14 is connected to the support member 10 to be swingable about the center of curvature 32a of the guide rail 32, and the actuator 40 is connected to a connecting rod 46 interconnecting the first joint 20 and the second link 26 in the first link 22.
Further, the length reducing mechanism 70 includes a slider gear 70a fastened to the slider 34, a link gear 70b meshed with the slider gear 70a and connected to the actuator 40, and a rocker arm 42 fastened at its one end with the link gear 70b and rotatably connected at its other end to the connecting rod 46, and the link gear 70b is driven by the actuator 40 to rotate the rocker arm 42 to move the connecting rod 46 backward (the length of the first link 22 is virtually reduced) such that the length d from the third joint 30 to the swing fulcrum is reduced.
Further, number of teeth of the slider gear 70a is larger than that of the link gear 70b.
In the second embodiment, the length reducing mechanism 70 includes one of components of a worm gear mechanism 86 having a worm 86a and a gear 86b fastened to the slider 34 and other thereof fastened to the connecting rod 46 and also connected to the actuator 40, and the other is driven by the actuator 40 to move the connecting rod 46 backward such that the length d from the third joint 30 to the swing fulcrum is reduced.
In the third embodiment, the length reducing mechanism 70 includes a guide 90 formed on the slider 34 and a second slider 92a, 92b movably engaged with the guide 90 and also fastened to the connecting rod 46, and the second slider 92a, 92b is driven by the actuator 40 to move the connecting rod 46 backward such that the length d from the third joint (more precisely the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) is reduced.
In the fourth embodiment, the length reducing mechanism 70 includes a link mechanism 94 movably connecting the slider 34 with the connecting rod 46, and the link mechanism 94 is driven by the actuator 40 to move the connecting rod 46 backward such that the length d from the third joint 30 (more precisely the joint shaft 30a thereof) to the swing fulcrum (center of curvature 32a) is reduced.
In the fifth to seventh embodiments, it is configured to have a walking assist device D having a support member (load transmitting member) 10 adapted to support a user P and transmit user's body weight, a pair of leg links 14 each connected to the support member 10 through a first joint 20 constituted of a swing mechanism to be swingable about a swing fulcrum 32a and having a first link 22 and a second link 26 connected to the first link 22 through a second joint (third joint 30), and actuators (electric motor) 40, each of the actuators 40 being operated to displace the first link 22 and the second link 26 relative to each other to produce an assist force that assists at least part of the user P's body weight so as to assist the user P to walk, wherein the leg link 14 includes a third link 100, 200 connected to the first joint 20, and the third link 100, 200 and the first link 22 are interconnected by a third joint (fourth joint) 102, 202 to be movable relative to each other.
More specifically, the leg link 14 includes the third link 100, 200 connected to the first joint 20, and the third link 100, 200 and the first link 22 are interconnected by the third joint (fourth joint) 102, 202 to be movable relative to each other, such that the forward protruding amount of the second joint to be protruded with change of the angle between the first link 22 and the second link 26 about the second joint (third joint) 30 is changed.
Further, movement of the second joint 30 describes trajectory having at least one inflection point Pi as viewed from side when the actuator (electric motor) 40 is operated to displace the first link 22 and second link 26 relative to each other.
Further, length from the second joint 30 to the swing fulcrum 32a is changed in line with trajectory having nonlinear characteristics as viewed from side as the angle (knee joint angle) between the first link 22 and the second link 26 about the second joint 30 is decreased when the actuator (electric motor) 40 is operated to displace the first link 22 and second link 26 relative to each other.
The device further includes a fourth link (bell crank 104, crank 204) connected to the first link 22 and a fifth link (connecting rod 106, 206) connected at its one end to the fourth link and at other end to the third link 100, 200, and a quadric-link mechanism 110, 210 constituted of the first, third, fourth and fifth links is driven by the actuator.
Further, the quadric-link mechanism 110, 210 establishes a dead point at which at least three (rotary shaft 100b1 of the rocker arm 100b, rotary shaft 104c1 of the one crank 104c of the bell crank, rotary shaft 104d1 of the other crank 104d of the bell crank 104, rotary shaft 200b1 of the rocker arm 200b, rotary shaft 204a of the crank 204, other rotary shaft 204b of the crank 204) of kinematic pair points are positioned in a straight line.
Further, a drive force of the actuator 40 is distributed to the first link 22 and the second link 26 to drive them.
Further, the second link 26 is connected to a second quadric-link mechanism 112, 212 and the drive force of the actuator 40 is distributed to the second link 26 through the second quadric-link mechanism.
In the seventh embodiment, the second link 26 is connected to a chain mechanism 120 and the drive force of the actuator 40 is distributed to the second link 26 through the chain mechanism 120.
Further, the second quadric-link mechanism 112, 212 shares at least one (rotary shaft 104b of the bell crank 104, rotary shaft 200b1 of the rocker arm 200b (and connecting rod 206)) of kinematic pair points with the first quadric-link mechanism 110, 210.
Although explained using the embodiments, the invention is not limited to the embodiments and various modifications are possible. For example, the length reducing mechanism 70 comprises the gear mechanism, worm gear mechanism or the like in the first to fourth embodiments but it should not be limited thereto.
In the first to seventh embodiments, although the actuator is exemplified by the electric motor 40, it should not be limited thereto.
Although the output shaft of the motor 40 is located at the bell crank 104 in the fifth embodiment and at the rotary shaft of the crank 204 in the sixth embodiment, the invention can be modified in the various manners, including the location of the output shaft of the motor 40.
According to this invention, in a walking assist device having a pair of leg links each connected to a support member through a first joint and having a first link and a second link connected to the first link through a second joint, and actuators, each of the actuators being operated to displace the first link and the second link relative to each other to produce an assist force that assists at least part of user's body weight so as to assist the user to walk, a forward protruding amount of the second joint to be protruded with change of an angle between the first link and the second link about the second joint is changed. With this, where the second joint is corresponding to the knee joint, it becomes possible to change, i.e., decrease the forward protruding amount of the second joint to be protruded from the trunk of the user with change of the angle about the second joint, thereby decreasing the inertia force about the vertical axis, while mitigating the unnatural impression of the appearance.
D Walking assist device, 10 Support member, 10a Seat, 10b Support frame, 10c Back rest, 10d Grip, 12 Shoe unit, 12a Shoe, 12b Connecting member, 12c Insole, 14 Leg link, 16 Drive mechanism, 20 First joint, 22 First link, 24 Second joint, 26 Second link, 30 Third joint, 32 Guide rail, 32a Center of curvature (swing fulcrum), 34 Slider, 36 Roller, 40 Actuator (electric motor), 40a Speed reducer, 40b Output shaft, 42 Rocker arm, 44 Driven crank arm, 46 Connecting rod, 50 Battery, 60 Pressure sensor, 62 Force sensor, 64 Controller, 70 Length reducing mechanism, 70a Slider gear, 70b Link gear, 72 Linear motion shaft, 72a Helical thread groove, 74 Ball screw mechanism, 74a Nut member, 76 Case, 76a Main case, 76b Side case, 80 Support shaft, 82 Cylindrical member, 84 Belt pulley mechanism, 84a Drive pulley, 84b Driven pulley, 84c Belt, 86 Worm gear mechanism, 86a Worm, 86b Gear, 90 Guide, 92 Second slider, 94 Link mechanism, 94a Third link, 94b Fourth link, 100, 200 Third link, 100a, 200a Link member, 100b, 200b Rocker arm, 102, 202 Fourth joint (third joint), 104 Bell crank, 104a Ball bearing, 104b Rotary shaft, 104c One crank, 104d Other crank, 204 Crank, 106, 206 Connecting rod, 110, 210 First quadric-link mechanism, 112, 212 Second quadric-link mechanism, 120 Chain mechanism, 122 Idler
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-018291 | Jan 2009 | JP | national |
| 2009-287917 | Dec 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/050535 | 1/19/2010 | WO | 00 | 7/27/2011 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2010/087245 | 8/5/2010 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20080009778 | Hiki | Jan 2008 | A1 |
| Number | Date | Country |
|---|---|---|
| 2007-020909 | Feb 2007 | JP |
| 2008-012224 | Jan 2008 | JP |
| Entry |
|---|
| Japanese Office Action with pertinent English translation dated Oct. 9, 2013, 3 pages. |
| German Office Action and Translation, 10 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20110306907 A1 | Dec 2011 | US |
