Technical Field
[0001] The present specification relates to an assistive device configured to assist in
transferring a care receiver.
Background Art
[0002] The need for assisting devices has increased with the aging of society. Assistive
devices are generally driven by an actuator to move a support section supporting a
part of the care receiver's body. The introduction of assistive devices reduces the
physical burden on caregivers and care receivers, thereby mitigating shortages in
caregiver staff. As an example of an assistive device, there is a device configured
to assist in transferring a care receiver from a sitting posture. Examples of techniques
relating to this type of assistive device are disclosed in Patent Literature 1 and
2.
[0003] The body transferring device of Patent Literature 1 includes a traveling section
equipped with wheels, a support section positioned above the traveling section to
support the care receiver, and a driving section to drive the support section in the
height direction. Further, the arc-shaped swinging operation of the support section
is performed by driving by a driving section equivalent to an actuator. With this,
the caregiver can easily and quickly transfer the care receiver while preventing injury
to the caregiver's back.
[0004] Further, the assisting robot of Patent Literature 2 includes a lifting and lowering
section that moves in an up-down direction with respect to a base, an arm that is
swingably provided in the lifting and lowering section, and a support section that
is provided at the distal end of the arm. The lifting and lowering section and the
arm are driven by separate actuators to perform a two-stage operation. With this,
the lifting and lowering section and the arm can be operated in coordination with
each other, and discomfort to the care receiver can be suppressed.
Patent Literature
Summary of the Invention
Technical Problem
[0006] In Patent Literature 1, since the support section only swings in an arc, it is not
always possible for the care receiver to use it comfortably. On the other hand, in
Patent Literature 2, since the lifting and lowering section and the arm are independently
operated with the use of two actuators, transferring the care receiver becomes smooth
and more comfortable. However, the use of two actuators leads to increased costs.
[0007] It is an object of the present specification to solve the problem of providing an
assistive device in which multiple members are operated by using one actuator to make
using the device more comfortable for the care receiver.
Solution to Problem
[0008] The present specification discloses an assistive device configured to assist in transferring
a care receiver, the assistive device comprising: a base; an arm, being provided on
the base, swingable in a front-rear direction; a support section, supporting a part
of a body of the care receiver, which is provided on the arm to be swingable in a
front-rear direction; an actuator having a main body section, which is provided on
the base and tiltable in a front-rear direction, and a movable section configured
to extend and retract from the main body section; and a linking mechanism having a
first linking member, which is swingably provided on the arm and connected to the
movable section, and a second linking member, which is fixed to the support section
and engaged with the first linking member; wherein the linking mechanism transfers
a first motion, in which the movable section is extended from a shortened position
to a predetermined intermediate position, to a forward swinging motion of the support
section; and transfers a second motion, in which the movable section is extended from
the intermediate position to a fully-extended position, to a forward swinging motion
of the arm.
Advantageous Effect of the Invention
[0009] With the assistive device disclosed in this specification, a single actuator can
be used to drive the forward swinging of the support section and the forward swinging
of the arm. As a result, transferring the care receiver becomes smooth and more comfortable
for the care receiver. Also, the cost is low compared to the prior art using two actuators.
Brief Description of Drawings
[0010]
[Fig. 1] A perspective view of an assistive device of an embodiment as viewed obliquely
from the rear.
[Fig. 2] A side cross-sectional view of the assistive device showing an initial state
when assisting in transferring a care receiver.
[Fig. 3] A side cross-sectional view of the assistive device showing an intermediate
state when assisting in transferring the care receiver.
[Fig. 4] A side cross-sectional view of the assistive device showing a final state
when assisting in transferring the care receiver.
[Fig. 5] A partial enlarged view of the assistive device in the initial state, showing
a configuration and operation of the linking mechanism.
[Fig. 6] A partial enlarged view of the assistive device in the intermediate state,
showing a configuration and operation of the linking mechanism.
[Fig. 7] A partial enlarged view of the assistive device in the initial state, showing
a configuration of an arm restricting mechanism.
[Fig. 8] A partial enlarged view of the assistive device in the intermediate state,
showing a configuration and operation of the arm restricting mechanism.
[Fig. 9] A perspective view of an upper portion of the arm from above at an oblique
angle.
[Fig. 10] A side cross-sectional view showing an unexpected swinging motion of the
arm with the movable section in an intermediate position.
Description of Embodiments
1. Configuration of assistive device 1 of the embodiment
[0011] Assistive device 1 of the embodiment will be described with reference to Figs. 1
to 10. Fig. 1 is a perspective view of assistive device 1 of the embodiment as viewed
obliquely from the rear. Fig. 2 is a side cross-sectional view of assistive device
1 showing an initial state when assisting in transferring care receiver M. Fig. 3
is a side cross-sectional view of assistive device 1 showing an intermediate state
when assisting in transferring care receiver M. Fig. 4 is a side cross-sectional view
of assistive device 1 showing a final state when assisting in transferring care receiver
M.
[0012] Assistive device 1 assists in transferring care receiver M between two different
places, for example, between a bed and a wheelchair or between a wheelchair and a
toilet seat. Assistive device 1 supports the trunk of care receiver M and assists
in transferring of care receiver M from a sitting posture to an in-transit posture,
and in seating of care receiver M from the in-transit posture to the sitting posture.
Here, the in-transit posture is a posture in which the buttocks are separated from
the seat surface and includes a standing posture and a stooping posture. That is,
the in-transit posture includes a state in which the upper body stands upright, a
state in which the upper body is bent forward, and the like. Further, in cases where
the two places between which transferring takes place are separated from each other,
assistive device 1 can transfer care receiver M in the in-transit posture.
[0013] Assistive device 1 includes base 2, arm 3, support section 4, actuator 5, linking
mechanism 6, arm restricting mechanism 7, a control section (not shown), and the like.
Base 2 is has foot mount 21, rear wheels 23, base rods 24, lower leg contact 25, mounting
plates 26, front wheels 28, and the like. Foot mount 21 is disposed in a substantially
horizontal manner in the vicinity of floor F. Actuator bearing section 22 protrudes
upward at the front of the upper face of foot mount 21. A pair of left and right rear
wheels 23 are provided on the left and right at the rear of foot mount 21.
[0014] The pair of left and right base rods 24 are provided so as to face forward from the
left and right sides of the front face of foot mount 21. Base rods 24 are bent upward
from the front and then extend backward in a slightly inclined manner. Lower leg contact
25 is provided on the upper portion of the two base rods 24 so as to face rearward.
Lower leg contact 25 is positioned above the front side of foot mount 21. Lower leg
contact 25 is made of a cushion material and designed to come in contact with the
lower leg vicinity of care receiver M.
[0015] The pair of right and left mounting plates 26 are fixed at positions slightly upward
along the bent portions which bend upward from the front of each base rod 24 and are
each disposed facing each other. Mounting plates 26 extend forward from base rod 24.
Arm support fitting 27 is provided at the upper portions of the pair of right and
left mounting plates 26. The pair of left and right front wheels 28 are provided at
the lower front portion of the pair of left and right mounting plates 26. Steering
functions of front wheels 28 and rear wheels 23 allow assistive device 1 to not only
move straight and turn but also move sideways and spin in place. Further, front wheels
28 have a locking function for restricting movement.
[0016] Arm 3 is made of rod-shaped member 31, front cover 36, upper cover 38, various structural
materials (not shown), and the like. Rod-shaped member 31 is a substantially U-shaped
rod-shaped member having an opening at the bottom. Both sides of lower end 32 of rod-shaped
member 31 are swingably supported by arm support fitting 27 of mounting plates 26.
As a result, arm 3 can swing in the front-rear direction with respect to base 2.
[0017] In order to restrict the swing angle of arm 3, a stopper mechanism (not shown) is
provided in the vicinity of arm support fitting 27. Rod-shaped member 31 extends upward
from the left and right lower ends 32, bends rearward and upward in at an intermediate
point, and merges with the upper portion toward the rear. The overall shape of arm
3 includes arm front section 34 extending upward from arm support fitting 27, and
arm upper section 35, connected to arm front section 34, extending obliquely upward
toward the rear.
[0018] Front cover member 36 constitutes arm front section 34. Front cover member 36 is
disposed in front of rod-shaped member 31 with a space therebetween. Front cover member
36 is formed by folding both side surfaces toward the rear, thereby defining an interior
cavity. Battery 37 is accommodated in the interior cavity of front cover member 36.
Battery 37 serves as a power source for actuator 5 and the control section.
[0019] Upper cover member 38 is formed so as to be continuous with front cover member 36
and constitutes arm upper section 35. Upper cover member 38 is disposed close to the
upper side of rod-shaped member 31. Upper cover member 38 is formed by folding both
side surfaces downward, thereby defining an interior cavity. Arm restricting mechanism
7, linking mechanism 6, and support section mounting fitting 33 are provided in that
order from the front lower side to the rear upper side in the interior cavity of upper
cover member 38. In Fig. 1, upper cover member 38 is not shown.
[0020] Support section 4 has trunk support section 41 and a pair of right and left underarm
support sections 45. Trunk support section 41 is swingably supported by support section
mounting fitting 33 of arm upper section 35. As a result, support section 4 can swing
in the front-rear direction with respect to arm 3. Trunk support section 41 has handle
42. Handle 42 has a substantially rectangular frame shape. Handle 42 is a part grasped
by care receiver M and is also a part grasped by the caregiver to move assistive device
1.
[0021] Trunk support section 41 consists of base plate 43 (see Fig. 5), trunk contact member
44, and the like. Base plate 43 consists of a highly rigid base plate material of
metal or resin and is formed in a substantially rectangular shape. Base plate 43 is
provided with handle 42, a part to be attached to support section attachment fitting
33 and second link member 62, which will be described later.
[0022] Trunk contact member 44, made of a flexible material, is larger than base plate 43
and is attached to the upper face of base plate 43. Trunk contact member 44 may have,
for example, a two-layer structure including an outer layer and a base layer. An example
of an outer layer material is polyurethane foam having low resilience, and an example
of a base layer material is polyurethane foam having low combustibility. Trunk support
section 41 supports the area from the chest to the abdomen of the trunk which is a
part of the body of care receiver M.
[0023] The pair of right and left underarm support sections 45 are attached to the right
and left chest areas of trunk support section 41. Underarm support sections 45 each
have an L-shape that bends at an obtuse angle. Each underarm support section 45 has
core member 46 (see Fig. 5), outer peripheral member 47, and the like. Core member
46 is formed, for example, by bending a circular rod or pipe, made of metal or hard
resin, into an L-shape.
[0024] Outer peripheral member 47, made of a cushion material, has a cylindrical shape and
covers the outer periphery of core member 46. The short linear portion from the proximal
attachment end to the bending point of underarm support section 45 becomes the shoulder
receiving portion, and the long linear portion from the bending point to the distal
end is the underarm inserting portion. The shoulder receiving portion supports the
front surface of the shoulder of care receiver M. The underarm inserting portions
of the pair of underarm support sections 45 are each inserted into both sides of the
trunk of care receiver M. Trunk support section 41 and underarm support sections 45
may be provided with a detachable cover made of cloth or leather.
[0025] Actuator 5 includes main body section 51, movable section 52, motor 53, and the like.
Main body section 51 is tiltably supported by actuator support section 22 of base
2. As a result, actuator 5 tilts in the front-rear direction. Movable section 52 expands
and contracts from main body section 51. More specifically, movable section 52 extends
from the shortened position to the fully-extended position through a predetermined
intermediate position, and contracts in the opposite direction. The first operation
consists of movable section 52 extending from the shortened position to the intermediate
position, and the second operation consists of movable section 52 extending from the
intermediate position to the fully-extended position.
[0026] For example, the stroke length of the first operation can be 30 mm, and the stroke
length of the second operation can be 60 mm. The distal end of movable section 52
is connected to connecting pin 613 of linking mechanism 6, which will be described
later. Motor 53 is provided in main body section 51. Motor 53 is controlled in the
direction of the current flowing by the control section (not shown in the drawings)
so as to drive the expanding and contracting operation of movable section 52. Instead
of motor 53, another type of driving source, such as a pressure driving source using
oil pressure or air pressure, can be used.
[0027] Linking mechanism 6 includes first linking member 61, second linking member 62, restricting
member 63, and the like. Fig. 5 is a partial enlarged view of assistive device 1 in
an initial state, showing a configuration and operation of linking mechanism 6. Fig.
6 is a partial enlarged view of assistive device 1 in an intermediate state, showing
a configuration and operation of linking mechanism 6.
[0028] First linking member 61 is an elongated member having support point 611, forearm
section 612, and posterior arm section 616. Support point 611 is disposed near the
center of arm upper section 35. Support point 611 is supported by a structural member
of arm 3 so as to be swingable. As a result, first linking member 61 swings about
support point 611.
[0029] Forearm section 612 extends forward from support point 611. Connecting pin 613 is
provided at a lower portion near the front of forearm section 612. Connecting pin
613 connects forearm section 612 and the distal end of movable section 52. Restricting
protrusion 614 is formed on an upper portion of forearm section 612 toward the front.
Posterior arm section 616 extends rearward from support point 611. Engagement pin
617 is provided at the rear of posterior arm section 616 so as to extend in the left-right
direction. Engagement pin 617 engages with second link member 62 by pushing second
link member 62 from the counterclockwise direction in Fig. 5.
[0030] Second link member 62 is fixed to base plate 43 of support section 4. As a result,
support section 4 and second link member 62 swing integrally about support section
mounting fitting 33. Restricting member 63 is fixed to a structural member in the
front of arm upper section 35. Restricting protrusion 614 of first linking member
61 is able to come in contact with restricting member 63.
[0031] In the initial state shown in Fig. 5, movable section 52 of actuator 5 is in the
shortened position. First linking member 61 swings clockwise, and second linking member
62 swings counterclockwise. There is a gap between restricting protrusion 614 of first
linking member 61 and restrictive member 63. Movable section 52, which has started
the first operation, extends as indicated by arrow A1. Consequently, forearm section
612 of first linking member 61 is pushed via connecting pin 613. As a result, first
linking member 61 swings counterclockwise as indicated by arrow A2.
[0032] As first linking member 61 swings counterclockwise, engagement pin 617 of posterior
arm section 616 swings and drives second linking member 62. Second link member 62
swings in the clockwise direction as indicated by arrow A3, and support section 4
swings in the forward direction as indicated by arrow A4. That is, linking mechanism
6 transfers the first motion, in which movable section 52 extends from the shortened
position to the predetermined intermediate position, to the forward swinging motion
of support section 4. This operation is continued until movable section 52 extends
to a predetermined intermediate position, and the state shown in Fig. 6 is reached.
[0033] In the intermediate state shown in Fig. 6, restricting protrusion 614 of first linking
member 61 abuts restricting member 63. This restricts further swinging of first linking
member 61. Thereafter, movable section 52 which has started the second motion extends
as indicated by arrow A5. Forearm section 612 of first linking member 61 then directly
transfers the second motion of movable section 52 to arm 3. As a result, arm 3 swings
forward about arm support fitting 27 as indicated by arrow A6. As the swinging of
arm 3 continues, actuator 5 tilts forward as indicated by arrow A7. That is, linking
mechanism 6 transfers the second motion in which movable section 52 extends from the
intermediate position to the fully-extended position to the forward swinging motion
of arm 3.
[0034] Arm restricting mechanism 7 includes restricting guide member 71, biasing member
75, and the like. Fig. 7 is a partial enlarged view of assistive device 1 in the initial
state, showing a configuration of arm restricting mechanism 7. Fig. 8 is a partial
enlarged view of assistive device 1 in the intermediate state, showing a configuration
and operation of arm restricting mechanism 7.
[0035] Restricting guide member 71 is a member having support point 72 at one end on the
front upper side and biasing point 73 at the other end on the rear lower side. Restricting
guide member 71 further has elongated hole 74 extending obliquely between support
point 72 and urging point 73. Support point 72 is disposed at predetermined position
3A near the upper portion of arm front section 34 and is supported by the structural
member so as to be swingable. Elongated hole 74 movably accommodates connecting pin
613, that is, elongated hole 74 movably accommodates the distal end of movable section
52.
[0036] A coil spring can be used as biasing member 75. One end 751 of the rear upper side
of biasing member 75 is locked to upper position 3B of arm 3. Upper position 3B of
arm 3 is located above predetermined position 3A. The other end 752 of the front lower
side of biasing member 75 is engaged with urging point 73 of restricting guide member
71. Biasing member 75 urges upper position 3B of arm 3 toward restricting guiding
member 71, as indicated by arrow F1. In other words, biasing member 75 urges upper
position 3B of arm 3 toward movable section 52.
[0037] In the initial state shown in Fig. 7, movable section 52 of actuator 5 is in the
shortened position. At this time, connecting pin 613 is positioned at the rear lower
end of elongated hole 74. Here, when movable section 52 starts the first motion, connecting
pin 613 moves forward and upward in elongated hole 74 in parallel with the swinging
motion of first linking member 61. Further, restricting guide member 71 swings clockwise
about support point 72. In the configuration of the present embodiment, restricting
guide member 71 swings 24 degrees in the first motion of movable section 52. This
motion continues until movable section 52 extends to a predetermined intermediate
position and restricting protrusion 614 comes into contact with restricting member
63, and the state shown in Fig. 8 is reached.
[0038] In the intermediate state shown in Fig. 8, connecting pin 613 is positioned at the
front upper end of elongated hole 74. Thereafter, when movable section 52 starts the
second motion, arm 3 swings, but the relative positional relationship between arm
3 and arm restricting mechanism 7 does not change. From the initial state to the final
state of assistive device 1, biasing member 75 urges upper position 3B of arm 3 toward
movable section 52.
[0039] The control section (not shown) is composed of an operating device, a control main
body section, and the like. The operating device has an up-button and a down-button
for operating actuator 5, and is operated by the caregiver. The control main body
section is configured by a computer device having a CPU and is operated with software.
The control main body section controls the direction of the current flowing through
motor 53 of actuator 5 in accordance with operation information acquired from the
operation device.
2. Operation, action, and effect of assistive device 1 of the embodiment
[0040] Next, the operation, action, and effect of assistive device 1 of the embodiment will
be described. Hereinafter, the control and operation of the lifting mode for assisting
in transferring care receiver M will be described. In the lifting mode, assistive
device 1 operates from the initial state shown in Fig. 2, through the intermediate
state shown in Fig. 3, to the final state shown in Fig. 4. When assisting in seating
care receiver M, assistive device 1 operates in the reverse direction in substantially
the reverse order of transferring.
[0041] First, the caregiver returns movable section 52 of actuator 5 to the shortened position
shown in Fig. 2. Next, the caregiver grasps handle 42 and moves assistive device 1
toward care receiver M in the sitting posture. Care receiver M inserts the lower body
into the region below support section 4 and places both feet on foot mount 21. Care
receiver M can obtain a stable posture by allowing a portion of the lower legs to
come in contact with lower leg contact 25.
[0042] Next, care receiver M tilts the trunk forward to bring the trunk in contact with
trunk support section 41, and rests both underarms on underarm support sections 45.
At this time, since trunk support section 41 is swung into an upright direction, the
forward inclination angle of the body can be small. Further, since underarm support
sections 45 are substantially horizontal or slightly lowered to the rear, care receiver
M can easily rest on underarm support sections 45. At this time, the posture of care
receiver M is the initial posture. The series of motions of care receiver M described
above may be assisted by the caregiver. In the initial posture, the buttocks of care
receiver M are seated on the seating surface. Thus, care receiver M is in a comfortable
posture because the load due to body weight is supported by the buttocks.
[0043] Next, the caregiver starts to control the lifting mode. As a result, movable section
52 of actuator 5 starts the first motion and expands, and first linking member 61
swings counterclockwise in Fig. 2. Arm 3 maintains the rear position of the initial
state. As first linking member 61 swings, support section 4 swings forward in a coordinated
manner with second linking member 62. At this time, since underarm support sections
45 are lowered forward, care receiver M is restricted from moving backward and does
not fall off support section 4.
[0044] By the swinging motion of support section 4, the forward tilted state of the upper
body of care receiver M gradually progresses. When movable section 52 extends to a
predetermined intermediate position, the state shown in Fig. 3 is obtained. In the
state shown in Fig. 3, restricting protrusion 614 comes into contact with restricting
member 63, and the swinging of first linking member 61 is completed. Accordingly,
the swinging of support section 4 is also completed. At this time, the buttocks of
care receiver M have just separated from the seating surface.
[0045] Further, when movable section 52 starts the second motion, arm 3 is driven by movable
section 52 to swing in the clockwise direction in Fig. 3. At the same time, actuator
5 tilts forward. Further, support section 4 maintains a constant orientation with
respect to arm 3. This operation is continues until the final state of Fig. 4 in which
movable section 52 expands to the fully-extended position and arm 3 reaches the front
position. As a result, care receiver M tilts further forward while the upper body
moves obliquely forward and upward. As a result, as shown in Fig. 4, care receiver
M assumes transferring posture in which the buttocks are greatly elevated from the
seating surface and the legs are extended.
[0046] With assistive device 1 of the embodiment, it is possible to drive the forward swinging
of support section 4 and the forward swinging of arm 3 using one actuator 5. As a
result, transferring care receiver M becomes smooth and more comfortable. Also, the
cost is low compared to the prior art using two actuators.
[0047] Further, in assistive device 1 of the embodiment, disengaging second linking member
62 from first linking member 61 is allowed. That is, second linking member 62 can
swing clockwise away from engagement pin 617 of first linking member 61 (see Fig.
10). As a result, support section 4 freely swings forward. Therefore, it is possible
to enlarge the region below support section 4, and care receiver M can easily insert
the lower body. Further, the thighs of care receiver M will never be held by strong
force.
[0048] Fig. 9 is a perspective view of the upper portion of arm 3 from above at an oblique
angle. As shown, the movable first linking member 61 and second linking member 62
are covered by upper cover member 38. As a result, safety is improved, and the appearance
is simplified and the aesthetic appearance is improved. Further, arm 3 is formed by
connecting arm front section 34 and arm upper section 35, and actuator 5 is disposed
close to arm front section 34. Thus, a spacious region is secured below support section
4, and care receiver M does not feel cramped.
3. Action and effect of arm restricting mechanism 7
[0049] Next, the action and effect of arm restricting mechanism 7 will be described. In
assistive device 1 of the embodiment, base 2, arm 3, actuator 5, and first linking
member 61 constitute a four-node link, and the degree of freedom of motion remains.
In other words, when an external force is applied, the shape of the four-node link
described above may change. Arm restricting mechanism 7 eliminates the degree of freedom
of the four-node link and restricts unexpected forward swinging of arm 3. Fig. 10
is a side cross-sectional view showing an unexpected swinging motion of arm 3 with
movable section 52 in an intermediate position.
[0050] As shown in Fig. 10, it is assumed that an external force is applied in a forward
direction to support section 4 in a configuration in which arm restricting mechanism
7 is not provided. In this case, first, support section 4 freely swings forward. Nevertheless,
if a residual force remains, arm 3 swings forward. That is, arm 3 swings without operating
movable section 52. As can be seen by comparing Figs. 3 and 10, arm 3 swings by an
angle α in an unexpected motion. This occurs when care receiver M vigorously rides
on support section 4. As a result, care receiver M feels uneasy about the unexpected
swinging motion of arm 3 and feels less comfortable.
[0051] Arm restricting mechanism 7 shown by a broken line in Fig. 10 restricts the unexpected
swinging motion of arm 3 by always accommodating the position of connecting pin 613
inside elongated hole 74. With the present embodiment, even if the degree of freedom
remains in linking mechanism 6, arm restricting mechanism 7 eliminates the degree
of freedom of linking mechanism 6 and restricts the unexpected motion of arm 3. Therefore,
with assistive device 1 of the embodiment, it is possible to restrict the unexpected
motion of arm 3 and ensure the comfort of care receiver M.
[0052] Further, arm restricting mechanism 7 does not hinder the driving by actuator 5. If
the swinging of arm 3 in the forward direction is merely restricted, arm 3 may be
biased in the rearward direction by using the biasing member. In this case, however,
the rearward urging force hinders the driving by actuator 5. On the other hand, with
the present embodiment, it is possible to restrict the unexpected motion of arm 3
without requiring an increase in the output of actuator 5.
4. Modifications and applications of the embodiments
[0053] Various modifications and applications of the present embodiment are possible including
changes in the shapes and sizes of the constituent members.
Reference Signs List
[0054] 1: Assistive device, 2: Base, 22: Actuator bearing section, 27: Arm support seat,
3: Arm, 31: Rod-shaped member, 33: Support section attachment seat, 38: Upper cover
member, 3A: Predetermined position, 3B: Upper position, 4: Support section, 5: Actuator,
51: Main body section, 52: Movable section, 53: Motor, 6: Linking mechanism, 61: First
linking member, 611: Support point, 612: Forearm section, 613: Connecting pin, 614:
Restricting protrusion, 616: Posterior arm section, 617: Engagement pin, 62: Second
linking member, 63: Restricting member, 7: Arm restricting mechanism, 71: Restricting
guide member, 74: Elongated hole, 75: Biasing member