BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates generally to a furniture and more particularly, to
a base seat adapted for being used with a bed, a chair or a sofa and provided with
a function of swinging in any direction, i.e. universal direction.
2. Description of the Related Art
[0002] Most of the conventional beds, chairs or sofas are configured to be placed on ground
or floor in a stationary manner; however, some of the conventional chairs or sofas
are designed as being swingable in a single direction. For example, conventional rocking
chairs are generally swingable back and forth. After using the conventional rocking
chairs having a monotone swinging direction for a certain period of time, users may
feel bored and/or fatigue. Further, the seats of the conventional rocking chairs usually
have a large inclined angle during swinging. Such feature easily makes users feel
uneasy and/or uncomfortable, resulting in that users may be unable to fully relax.
In another aspect, swingable beds are seldomly available in commercial market.
SUMMARY OF THE INVENTION
[0003] The present invention has been accomplished in view of the above-noted circumstances.
It is an objective of the present invention to provide a base seat for being used
with a bed, chair or sofa, which can swing in any direction, i.e. universal direction,
or at least multi-directions, thereby preventing users from feeling bored and/or fatigue
due to a monotone swinging motion.
[0004] Another objective of the present invention is to provide a base seat for being used
with a bed, chair or sofa, which has proper variable inclined angles during swinging,
such that users may feel easy and comfortable to fully relax.
[0005] To attain the above objectives, the present invention provides a base seat, which
is adapted for being used with a bed, a chair or a sofa, comprising a fixation base,
a first rocking mount, a first drive device, a second rocking mount, and a second
drive device. The fixation base includes a front frame body and a rear frame body.
The first rocking mount is connected with the front frame body of the fixation base
via two front suspension arms in a way that each of the two front suspension arms
has a top end pivotally connected with the front frame body and a bottom end pivotally
connected with the first rocking mount, and a distance between the top ends of the
two front suspension arms is smaller than a distance between the bottom ends of the
two front suspension arms. The first rocking mount is also connected with the rear
frame body of the fixation base via two rear suspension arms in a way that each of
the two rear suspension arms has a top end pivotally connected with the rear frame
body and a bottom end pivotally connected with the first rocking mount, and a distance
between the top ends of the two rear suspension arms is smaller than a distance between
the bottom ends of the two rear suspension arms. As such, the first rocking mount
is swingable leftward and rightward relative to the fixation base along a first arc
path with a variable inclined angle thereof. The first rocking mount comprises a right
frame body and a left frame body. The first drive device is disposed between the fixation
base and the first rocking mount to drive the first rocking mount to reciprocatingly
swing leftward and rightward relative to the fixation base. The second rocking mount
is connected with the left frame body of the first rocking mount via two left suspension
arms in a way that each of the two left suspension arms has a top end pivotally connected
with the left frame body and a bottom end pivotally connected with the second rocking
mount, and a distance between the top ends of the two left suspension arms is smaller
than a distance between the bottom ends of the two left suspension arms. The second
rocking mount is also connected with the right frame body of the first rocking mount
via two right suspension arms in a way that each of the two right suspension arms
has a top end pivotally connected with the right frame body and a bottom end pivotally
connected with the second rocking mount, and a distance between the top ends of the
two right suspension arms is smaller than a distance between the bottom ends of the
two right suspension arms. As such, the second rocking mount is swingable forward
and backward relative to the first rocking mount along a second arc path with a variable
inclined angle thereof. The second rocking mount is configured to support the bed,
the chair or the sofa thereon. The second drive device is disposed between the first
rocking mount and the second rocking mount to drive the second rocking mount to reciprocatingly
swing forward and backward relative to the first rocking mount. As a result, the base
seat may have a function of swinging in any direction, i.e. universal direction, so
as to prevent users from feeling bored and/or fatigue due to a monotone swinging motion,
and provide a proper variation of the inclined angle during swinging, such that users
may feel easy and comfortable so as to fully relax.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention will become more fully understood from the detailed description
given herein below and the accompanying drawings which are given by way of illustration
only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a perspective view of a base seat according to a preferred embodiment of
the present invention;
FIG. 2 is an exploded view of the base seat of the preferred embodiment of the present
invention;
FIG. 3 is a front view of the base seat of the preferred embodiment of the present
invention;
FIGS. 4 and 5 are front views showing swinging motions of the base seat of the preferred
embodiment of the present invention;
FIG. 6 is a front view of a base seat of a first comparative exemplary embodiment;
FIGS. 7 and 8 are front views showing swinging motions of the base seat of the first
comparative exemplary embodiment;
FIG. 9 is a front view of a base seat of a second comparative exemplary embodiment;
and
FIGS. 10 and 11 are front views showing swinging motions of the base seat of the second
comparative exemplary embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0007] The structure and technical features of the present invention will be detailedly
described hereunder by a preferred embodiment and accompany drawings. FIGS. 1-3 show
a base seat 10 for providing swinging motions in multi-directions or universal direction
for a bed (not shown), a chair (not shown) or a sofa (not shown) to be fixedly positioned
thereon. The base seat 10 comprises a fixation base 20, a first rocking mount 30,
a first drive device 40, a second rocking mount 50, and a second drive device 60.
[0008] The fixation base 20 is shaped like a hollow rectangle frame including a front frame
body 22, a rear frame body 24, and two connecting rods 25 connecting the front and
rear frame bodies 22 and 24 together. The fixation base 20 further includes four support
legs 26 adapted for standing on a ground or a flat surface. To avoid slip, a base
pad 28 made of plastic material, rubber material or other anti-slip material is disposed
to the bottom portion of each support leg 26. As shown in FIG. 3, the fixation base
20 has an overall height H1.
[0009] The first rocking mount 30 is shaped like a hollow rectangle frame including a right
frame body 31, a left frame body 32, two connecting racks 33 connecting the right
and left frame bodies 31 and 32 together, and a bottom rack 34 disposed between the
two connecting racks 33. The first rocking mount 30 is connected with the front frame
body 22 of the fixation base 20 via two front suspension arms 36, and also connected
with the rear frame body 24 of the fixation base 20 via two rear suspension arms 37.
Each of the two front suspension arms 36 has a top end 361 pivotally connected with
the front frame body 22 and a bottom end 362 pivotally connected with the first rocking
mount 30 in such a way that a distance D1 between the top ends 361 of the two front
suspension arms 36 is smaller than a distance D2 between the bottom ends 362 of the
two front suspension arms 36. Each of the two rear suspension arms 37 has a top end
371 pivotally connected with the rear frame body 24 and a bottom end 372 pivotally
connected with the first rocking mount 30 in such a way that a distance D1 between
the top ends 371 of the two rear suspension arms 37 is smaller than a distance D2
between the bottom ends 372 of the two rear suspension arms 37. The pivotal portions
among the two front suspension arms 36, the two rear suspension arms 37 and the first
rocking mount 30, namely the bottom ends 362 and 372, are located at, but not limited
to, the four corners 38 of the first rocking mount 30. As such, the first rocking
mount 30 is swingable leftward and rightward relative to the fixation base 20 along
an arc path, namely a first arc path, in a way that the inclined angle of the first
rocking mount 30 will vary during the swinging motion thereof. When the first rocking
mount 30 is located at the center of the fixation base 20, the first rocking mount
30 has an overall height H2 substantially corresponding to the height H1 of the fixation
base 20 in a way that the top side 39 of the first rocking mount 30 is slightly higher
than the top side 29 of the fixation base 20.
[0010] The first drive device 40 comprises a first power source 41, a first crank 46, and
a first link 48. The first power source 41 is disposed to the bottom rack 34 of the
first rocking mount 30 and provided with a first motor 42, a first gear box 43, and
a first output shaft 44 extending in a front-and-rear direction. The first gear box
43 transmits an output power of the first motor 42 to the first output shaft 44. The
first crank 46 has an end connected with the first output shaft 44. The first link
48 has two ends pivotally connected with the first crank 46 and one of the connecting
rods 25 of the fixation base 20, respectively. As such, the first drive device 40
can drive the first rocking mount 30 to reciprocatingly swing leftward and rightward
relative to the fixation base 20.
[0011] The second rocking mount 50 is shaped like a hollow rectangle frame and connected
with the left frame body 32 of the first rocking mount 30 via two left suspension
arms 52, and also connected with the right frame body 31 of the first rocking mount
30 via two right suspension arms 54. Each of the two left suspension arms 52 has a
top end 521 pivotally connected with the left frame body 32 and a bottom end 522 pivotally
connected with the second rocking mount 50 in such a way that a distance D3 between
the top ends 521 of the two left suspension arms 52 is smaller than a distance D4
between the bottom ends 522 of the two left suspension arms 52. Each of the two right
suspension arms 54 has a top end 541 pivotally connected with the right frame body
31 and a bottom end 542 pivotally connected with the second rocking mount 50 in such
a way that a distance D3 between the top ends 541 of the two right suspension arms
54 is smaller than a distance D4 between the bottom ends 542 of the two right suspension
arms 54. The pivotal portions among the two left suspension arms 52, the two right
suspension arms 54 and the second rocking mount 50, namely the bottom ends 522 and
542, are located at, but not limited to, the four corners 56 of the second rocking
mount 50. As such, the second rocking mount 50 is swingable forward and backward relative
to the first rocking mount 30 along an arc path, namely a second arc path, in a way
that the inclined angle of the second rocking mount 50 will vary during the swinging
motion thereof. When the second rocking mount 50 is located at the center of the first
rocking mount 30, the second rocking mount 50 has an overall height H3 substantially
corresponding to the height H2 of the first rocking mount 30 in a way that the top
side 58 of the second rocking mount 50 is slightly higher than the top side 39 of
the first rocking mount 30. The top side 58 of the second rocking mount 50 is adapted
to support a bed, chair or sofa thereon.
[0012] The second drive device 60 comprises a second power source 61, a second crank 66,
and a second link 68. The second power source 61 is disposed to the bottom rack 34
of the first rocking mount 30 and provided with a second motor 62, a second gear box
63, and a second output shaft 64 extending in a left-and-right direction. The second
gear box 63 transmits an output power of the second motor 62 to the second output
shaft 64. The second crank 66 has an end connected with the second output shaft 64.
The second link 68 has two ends pivotally connected with the second crank 66 and the
second rocking mount 50, respectively. As such, the second drive device 60 can drive
the second rocking mount 50 to reciprocatingly swing forward and backward relative
to the first rocking mount 30, as shown in FIGS. 4 and 5.
[0013] With the above-mentioned structural design, when a bed, chair or sofa is installed
on the base seat 10 of the present invention, and more specifically when the bed,
chair or the sofa is fixedly mounted on the second rocking mount 50, the base seat
10 can be operated to drive the bed, chair or the sofa to swing forward and backward
or to swing leftward and rightward along an arc swinging path with an opening facing
upward. In particular, when the first drive device 40 and the second drive device
60 simultaneously work in a condition that the first output shaft 44 has a rotary
speed different from that of the second output shaft 64, the base seat 10 can drive
the bed, chair or the sofa to swing in any direction, i.e. universal direction, thereby
providing variable experiences to users so as to prevent the users from feeling bored
and/or fatigue due to a monotone swinging motion. Further, as shown in FIGS. 3-5,
by means of the structural feature that the suspension arms 36, 37, 52 and 54 are
arranged having narrower top distances and wider bottom distances, when the first
rocking mount 30 and the second rocking mount 50 swing, the first rocking mount 30
and the second rocking mount 50 may have proper inclined angles, which won't be too
tilted to make users feel uneasy, and won't be too gentle to make users feel mechanical
monotonous. In short, the base seat 10 of the present invention conforms to ergonomics,
so that the user feels stable and comfortable and can fully relax, thereby achieving
the objective of the present invention.
[0014] Moreover, since both the first power source 41 and the second power source 61 are
mounted to the base rack 34 of the first rocking mount 30, the base seat 10 of the
present invention may have a low center of gravity thereof, thereby reducing shake
of the base seat 10 when it is operated and effectively improving smoothness of operation.
[0015] The feature of motion of the present invention will be detailedly illustrated hereinafter.
Because the first and second rocking mounts 30 and 50 in the previous embodiment have
similar structures and similar motions, only the motion of the second rocking mount
50 will be described hereinafter for concise illustrative purpose. As shown in FIGS.
4 and 5, since the two left suspension arms 52 have a narrower top distance and a
wider bottom distance and the two right suspension arms 54 also have a narrower top
distance and a wider bottom distance, the second rocking mount 50 will slightly tilt
and the inclined angle of the second rocking mount 50 will slightly vary during the
period that the second rocking mount 50 is swinging back and forth. Compared to a
swing having a single hanging point, the aforesaid feature of the present invention
makes a user feels comfortable and relaxed because the swing having a single hanging
point will have a large variation of angle to make user feel excited and fun when
it is swinging.
[0016] The feature of motion of the base seat of the present invention will become more
fully understood from the detailed description of two comparative exemplary embodiments
hereinafter. FIG. 6 shows a first comparative exemplary embodiment having a structural
feature that the two left suspension arms 52a have a wider top distance and a narrower
bottom distance, thereby revealing a different motion. As shown in FIG. 7, when the
second rocking mount 50a swings forward, the second rocking mount 50a itself tilts
forward, and when the second rocking mount 50a swings backward, the second rocking
mount 50a itself tilts backward, as shown in FIG. 8. This feature of motion of the
second rocking mount 50a makes user feel that he/she is going to be swung out of the
second rocking mount 50a, i.e. feel unstable and uneasy, when the second rocking mount
50a is swinging forward and backward. In contrast, as shown in FIG. 4, when the second
rocking mount 50 of the present invention swings forward, the second rocking mount
50 itself tilts backward, and when the second rocking mount 50 swings backward, the
second rocking mount 50 itself tilts forward, as shown in 5. This feature of motion
of the second rocking mount 50 makes user feel that he/she is safely held on the second
rocking mount 50, i.e. feel stable and easy, when the second rocking mount 50 is swinging
forward and backward. Further, 9 shows a second comparative exemplary embodiment having
a structural feature that the two left suspension arms 52b are arranged parallel,
thereby revealing a different motion. As shown in 10, when the second rocking mount
50b swings forward, the second rocking mount 50b itself does not tilt, i.e. has an
unchanged angle, and when the second rocking mount 50b swings backward, the second
rocking mount 50b itself does not tilt either, as shown in 11. This feature may make
user feel mechanical monotonous, bored, and/or fatigue.
[0017] In other words, the present invention is an optimal design resulted from many experimental
tests, which may allow the user to fully relax and even partially solve the problem
of insomnia. According to experimental tests, when the first rocking mount 30 and
the second rocking mount 50 are respectively located at the middle points of their
swinging strokes, i.e. the first rocking mount 30 is located at the middle point of
the first arc path and the second rocking mount 50 is located at the middle point
of the second arc path, an included angle between one of the suspension arms 36, 37,
52 and 54 and a plumb line ranges preferably from 4 to 12 degrees, and more preferably
from 5 to 10 degrees, and best preferably from 6 to 8 degrees. In the previous embodiment,
the aforesaid included angle is set about 7 degrees. Based on the structural features
of the present invention, various modifications to the structure of the base seat
10 may be made. For example, for the first and second drive devices, any mechanism
having a reciprocating driving function may be used. Such variations are not to be
regarded as a departure from the scope of the invention, and all such modifications
as would be obvious to one skilled in the art are intended to be included within the
scope of the following claims.
1. Abase seat (10) for being used with a bed, a chair, or a sofa,
characterized in that the base seat (10) comprises:
a fixation base (20) having a front frame body (22) and a rear frame body (24);
a first rocking mount (30) connected with the front frame body (22) and the rear frame
body (24) of the fixation base (20) via two front suspension arms (36) and two rear
suspension arms (37), respectively, in a way that each of the two front suspension
arms (36) has a top end (361) pivotally connected with the front frame body (22) and
a bottom end (362) pivotally connected with the first rocking mount (30) in a way
that a distance (D1) between the top ends (361) of the two front suspension arms (36)
is smaller than a distance (D2) between the bottom ends (362) of the two front suspension
arms (36), and each of the two rear suspension arms (37) has a top end (371) pivotally
connected with the rear frame body (24) and a bottom end (372) pivotally connected
with the first rocking mount (30) in a way that a distance (D1) between the top ends
(371) of the two rear suspension arms (37) is smaller than a distance (D2) between
the bottom ends (372) of the two rear suspension arms (37), such that the first rocking
mount (30) is swingable leftward and rightward relative to the fixation base (20)
along a first arc path with a variable inclined angle thereof; the first rocking mount
(30) comprising a right frame body (31) and a left frame body (32);
a first drive device (40) disposed between the fixation base (20) and the first rocking
mount (30) to drive the first rocking mount (30) to reciprocatingly swing leftward
and rightward relative to the fixation base (20);
a second rocking mount (50) connected with the left frame body (32) and the right
frame body (31) of the first rocking mount via two left suspension arms (52) and two
right suspension arms (54), respectively, in a way that each of the two left suspension
arms (52) has a top end (521) pivotally connected with the left frame body (32) and
a bottom end (522) pivotally connected with the second rocking mount (50) in a way
that a distance (D3) between the top ends (521) of the two left suspension arms (52)
is smaller than a distance (D4) between the bottom ends (522) of the two left suspension
arms (52), and each of the two right suspension arms (54) has a top end (541) pivotally
connected with the right frame body (31) and a bottom end (542) pivotally connected
with the second rocking mount (50) in a way that a distance (D3) between the top ends
(541) of the two right suspension arms (54) is smaller than a distance (D4) between
the bottom ends (542) of the two right suspension arms (54), such that the second
rocking mount (50) is swingable forward and backward relative to the first rocking
mount (30) along a second arc path with a variable inclined angle thereof; the second
rocking mount (50) being configured to support the bed, the chair or the sofa; and
a second drive device (60) disposed between the first rocking mount (30) and the second
rocking mount (50) to drive the second rocking mount (50) to reciprocatingly swing
forward and backward relative to the first rocking mount (30).
2. The base seat of claim 1, characterized in that the first drive device (40) comprises a first power source (41), a first crank (46),
and a first link (48); the first power source (40) is disposed to the first rocking
mount (30) and provided with a first output shaft (44) extending in a front-and-rear
direction; the first crank (46) has an end connected with the first output shaft (44);
the first link (48) has two ends pivotally connected with the first crank (46) and
the fixation base (20), respectively.
3. The base seat of claim 2, characterized in that the first power source (41) comprises a first motor (42) and a first gear box (43)
transmitting an output power of the first motor (42) to the first output shaft (44).
4. The base seat of any of claims 1-3, characterized in that the second drive device (60) comprises a second power source (61), a second crank
(66), and a second link (68); the second power source (61) is disposed to the first
rocking mount (30) and provided with a second output shaft (64) extending in a left-and-right
direction; the second crank (66) has an end connected with the second output shaft
(64); the second link (68) has two ends pivotally connected with the second crank
(66) and the second rocking mount (50), respectively.
5. The base seat of claim 4, characterized in that the second power source (61) comprises a second motor (62) and a second gear box
(63) transmitting an output power of the second motor (62) to the second output shaft
(64).
6. The base seat of any of claims 1-5, characterized in that a height (H3) of a top side (58) of the second rocking mount (50) is higher than
a height (H2) of a top side (39) of the first rocking mount (30) and a height (H1)
of a top side (29) of the fixation base (20).
7. The base seat of any of claims 1-6, characterized in that the bottom ends (362) of the two front suspension arms (36) and the bottom ends (372)
of the two rear suspension arms (37) are disposed at four corners (38) of the first
rocking mount (30), respectively.
8. The base seat of any of claims 1-7, characterized in that the bottom ends (522) of the two left suspension arms (52) and the bottom ends (542)
of the two right suspension arms (54) are disposed at four corners (56) of the second
rocking mount (50), respectively.
9. The base seat of any of claims 1-8, characterized in that the fixation base (20) comprises four support legs (26); each of the four support
legs (26) has a bottom portion mounted with a base pad (28).
10. The base seat of any of claims 1-9, characterized in that when the first rocking mount (20) is located at a middle point of the first arc path,
an included angle between one of the two front suspension arms (36) and a plumb line
ranges from 4 to 12 degrees.
11. The base seat of claim 10, characterized in that when the first rocking mount (20) is located at the middle point of the first arc
path, the included angle ranges from 5 to 10 degrees.
12. The base seat of claim 10, characterized in that when the first rocking mount (20) is located at the middle point of the first arc
path, the included angle ranges from 6 to 8 degrees.
Amended claims in accordance with Rule 137(2) EPC.
1. A base seat (10) for being used with a bed, a chair, or a sofa, the base seat (10)
comprising:
a fixation base (20) having a front frame body (22) and a rear frame body (24);
a first rocking mount (30) connected with the front frame body (22) and the rear frame
body (24) of the fixation base (20) via two front suspension arms (36) and two rear
suspension arms (37), respectively, in a way that each of the two front suspension
arms (36) has a top end (361) pivotally connected with the front frame body (22) and
a bottom end (362) pivotally connected with the first rocking mount (30) in a way
that a first distance (D1) between the top ends (361) of the two front suspension
arms (36) is smaller than a second distance (D2) between the bottom ends (362) of
the two front suspension arms (36), and each of the two rear suspension arms (37)
has a top end (371) pivotally connected with the rear frame body (24) and a bottom
end (372) pivotally connected with the first rocking mount (30) in a way that a first
distance (D1) between the top ends (371) of the two rear suspension arms (37) is smaller
than a second distance (D2) between the bottom ends (372) of the two rear suspension
arms (37), such that the first rocking mount (30) is swingable leftward and rightward
relative to the fixation base (20) along a first arc path with a variable inclined
angle thereof; the first rocking mount (30) comprising a right frame body (31) and
a left frame body (32);
a first drive device (40) disposed between the fixation base (20) and the first rocking
mount (30) to drive the first rocking mount (30) to reciprocatingly swing leftward
and rightward relative to the fixation base (20);
characterized in that
a second rocking mount (50) connected with the left frame body (32) and the right
frame body (31) of the first rocking mount via two left suspension arms (52) and two
right suspension arms (54), respectively, in a way that each of the two left suspension
arms (52) has a top end (521) pivotally connected with the left frame body (32) and
a bottom end (522) pivotally connected with the second rocking mount (50) in a way
that a third distance (D3) between the top ends (521) of the two left suspension arms
(52) is smaller than a forth distance (D4) between the bottom ends (522) of the two
left suspension arms (52), and each of the two right suspension arms (54) has a top
end (541) pivotally connected with the right frame body (31) and a bottom end (542)
pivotally connected with the second rocking mount (50) in a way that a third distance
(D3) between the top ends (541) of the two right suspension arms (54) is smaller than
a forth distance (D4) between the bottom ends (542) of the two right suspension arms
(54), such that the second rocking mount (50) is swingable forward and backward relative
to the first rocking mount (30) along a second arc path with a variable inclined angle
thereof; the second rocking mount (50) being configured to support the bed, the chair
or the sofa; and
a second drive device (60) disposed between the first rocking mount (30) and the second
rocking mount (50) to drive the second rocking mount (50) to reciprocatingly swing
forward and backward relative to the first rocking mount (30).
2. The base seat of claim 1, characterized in that the first drive device (40) comprises a first power source (41), a first crank (46),
and a first link (48); the first power source (40) is disposed to the first rocking
mount (30) and provided with a first output shaft (44) extending in a front-and-rear
direction; the first crank (46) has an end connected with the first output shaft (44);
the first link (48) has two ends pivotally connected with the first crank (46) and
the fixation base (20), respectively.
3. The base seat of claim 2, characterized in that the first power source (41) comprises a first motor (42) and a first gear box (43)
transmitting an output power of the first motor (42) to the first output shaft (44).
4. The base seat of any of claims 1-3, characterized in that the second drive device (60) comprises a second power source (61), a second crank
(66), and a second link (68); the second power source (61) is disposed to the first
rocking mount (30) and provided with a second output shaft (64) extending in a left-and-right
direction; the second crank (66) has an end connected with the second output shaft
(64); the second link (68) has two ends pivotally connected with the second crank
(66) and the second rocking mount (50), respectively.
5. The base seat of claim 4, characterized in that the second power source (61) comprises a second motor (62) and a second gear box
(63) transmitting an output power of the second motor (62) to the second output shaft
(64).
6. The base seat of any of claims 1-5, characterized in that a third height (H3) of a top side (58) of the second rocking mount (50) is higher
than a second height (H2) of a top side (39) of the first rocking mount (30) and a
first height (HI) of a top side (29) of the fixation base (20).
7. The base seat of any of claims 1-6, characterized in that the bottom ends (362) of the two front suspension arms (36) and the bottom ends (372)
of the two rear suspension arms (37) are disposed at four corners (38) of the first
rocking mount (30), respectively.
8. The base seat of any of claims 1-7, characterized in that the bottom ends (522) of the two left suspension arms (52) and the bottom ends (542)
of the two right suspension arms (54) are disposed at four corners (56) of the second
rocking mount (50), respectively.
9. The base seat of any of claims 1-8, characterized in that the fixation base (20) comprises four support legs (26); each of the four support
legs (26) has a bottom portion mounted with a base pad (28).
10. The base seat of any of claims 1-9, characterized in that when the first rocking mount (20) is located at a middle point of the first arc path,
an included angle between one of the two front suspension arms (36) and a plumb line
ranges from 4 to 12 degrees.
11. The base seat of claim 10, characterized in that when the first rocking mount (20) is located at the middle point of the first arc
path, the included angle ranges from 5 to 10 degrees.
12. The base seat of claim 10, characterized in that when the first rocking mount (20) is located at the middle point of the first arc
path, the included angle ranges from 6 to 8 degrees.