BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates to mechanical devices and more particularly to a pneumatic
cylinder.
2. Description of Related Art
[0002] Conventionally, a pneumatic cylinder comprises a hollow body, an upper cover disposed
on a top of the hollow body, and a lower cover disposed on a bottom of the hollow
body. A space is formed in the hollow body for allowing a rotor to rotate. Further,
an electromagnetic valve is used to control the flow of gas, thereby allowing gas
to enter the hollow body or exiting gas out of the hollow body. Shapes and sizes of
the upper and lower covers are required to correspond to shapes and sizes of the different
hollow bodies. This in turn can complicate the manufacturing processes and increase
the manufacturing cost.
SUMMARY OF THE INVENTION
[0003] It is the object of this invention to provide an improved pneumatic cylinder.
[0004] This object is achieved by the subject matter of the independent claim.
[0005] Preferred embodiments of the invention are mirrored by the dependent claims.
[0006] By utilizing the invention, for increasing space of the housing, only length of the
hollow body is changed and shapes and sizes of the upper and lower covers are not
changed, production is made easy, and manufacturing cost is decreased. Further, the
invention is applicable to either fail-safe cylinder (FSC) or double-acting cylinder
(DAC).
[0007] The above and other objects, features and advantages of the invention will become
apparent from the following detailed description taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
FIG. 1 is a perspective view of a pneumatic cylinder according to a first preferred
embodiment of the invention;
FIG. 2 is an exploded view of the pneumatic cylinder;
FIG. 3 is a perspective, exploded view of the pneumatic cylinder showing the electromagnetic
valve separated from the housing and communication between the first openings and
the opening members;
FIG. 4 is a sectional view taken from line 4-4 to line 5-5 in FIG. 3;
FIG. 5 is a sectional view taken from line 6-6 to line 7-7 in FIG. 3;
FIG. 6 is a top view of the pneumatic cylinder with the upper cover removed to show
rotation of the rotor;
FIG. 7 is a top view of the pneumatic cylinder showing locations of the first openings
disposed on the hollow body;
FIG. 8 is a side elevation of the pneumatic cylinder showing locations of the first
openings disposed on the hollow body;
FIG. 9 is a left side view of the pneumatic cylinder showing locations of the first
openings disposed on sides of the upper and lower covers;
FIG. 10 is a right side view of the pneumatic cylinder showing locations of the first
openings disposed on the sides of the upper and lower covers;
FIG. 11 is a perspective view of the pneumatic cylinder showing locations of the first
openings disposed on a top of the upper cover;
FIG. 12 is another perspective view of the pneumatic cylinder showing locations of
the first openings disposed on a bottom of the lower cover;
FIG. 13 is a perspective view of a pneumatic cylinder according to a second preferred
embodiment of the invention, showing a gas compartment disposed at an end of the housing;
FIG. 14 is a side elevation of the pneumatic cylinder in FIG. 13;
FIG. 15 is a top view of the pneumatic cylinder of FIG. 13 with the upper cover removed
showing its operation;
FIG. 16 is a perspective view of a pneumatic cylinder according to a third preferred
embodiment of the invention, showing the gas compartment disposed on a top of the
upper cover of the housing; and
FIG. 17 is a top plan view of a pneumatic cylinder according to a fourth preferred
embodiment of the invention, showing a gas compartment disposed externally and connected
to the housing via a tube.
DETAILED DESCRIPTION OF THE INVENTION
[0009] Referring to FIGS. 1 to 12, a pneumatic cylinder 100 in accordance with a first preferred
embodiment of the invention comprises the following components as discussed in detail
below.
[0010] A housing 10 comprises a hollow body 11, an upper cover 12 and a lower cover 13.
The hollow body 11 includes a first part 111 having a fan-shaped cross-section and
a second part 112 having a half circular section formed with the first part 111. Inside
of the hollow body 11 are provided with a first compartment 113 on an upper portion
and a second compartment 114 on a lower portion. The first and second compartments
113, 114 communicate with each other and have the same shape. The upper cover 12 and
the lower cover 13 are shaped corresponding to a shape of the hollow body 11. The
upper cover 12 and the lower cover 13 are disposed on the first compartment 113 and
the second compartment 114 respectively, thereby forming an activation chamber 14
in the hollow body 11. The activation chamber 14 includes a first activation space
141 in the first part 111 and a second activation space 142 in the second part 112.
The first activation space 141 communicates with the second activation space 142.
A first hole 121 is formed through the upper cover 12 and a second hole 131 is formed
through the lower cover 13. The first hole 121 is aligned with the second hole 131.
[0011] The first part 111 includes a first arc surface 115 and two side surfaces 116 integrally
formed at two ends of the first arc surface 115 respectively. The second part 112
includes a second arc surface 117 having a width less than that of the first arc surface
115. The first arc surface 115 is opposite to the second arc surface 117 and the first
and second arc surfaces 115, 117 are convex.
[0012] A rotor 20 is disposed in the activation chamber 14 and may rotate an angle between
30-degree and 180-degree in the activation chamber 14. The rotor 20 includes a drive
shaft 21 and a blade 22. Two ends of the drive shaft 21 are rotatably disposed in
the first hole 121 and the second hole 131 respectively. The blade 22 is secured to
the drive shaft 21. The blade 22 rotates about the drive shaft 21 in the activation
chamber 14. The drive shaft 21 divides the blade 22 into a first section 221 and a
second section 222 having a length less than that of the first section 221. That is,
the first and second sections 221, 222 are not symmetrical by the division of the
drive shaft 21. The first section 221 may rotate in the first activation space 141
and the second section 222 may rotate in the second activation space 142. A seal 23
is provided around the blade 22 to prevent pressurized gas from leaking. A flat surface
15 is provided on a bottom of the upper cover 12 and another flat surface 15 is provided
on a top of the lower cover 13 respectively. The flat surfaces 15 correspond to the
rotor 20. As shown in FIG. 4 specifically, a plurality of segments are formed on an
inner surface of the hollow body 11 along an axial direction of the drive shaft 21
from line 4-4 to line 5-5 in FIG. 3 and the segments have the same shape and size.
As shown in FIG. 5 specifically, a plurality of segments are formed on an inner surface
of the hollow body 11 along the axial direction of the drive shaft 21 from line 6-6
to line 7-7 in FIG. 3 and the segments have the same shape and size.
[0013] Two first openings 31 are provided on two sides of the housing 10 respectively. Specifically,
the first openings 31 are provided on two sides of the hollow body 11 respectively
(see FIGS. 7 and 8). Alternatively, the first openings 31 are provided on one side
of the upper cover 12 and one side of the lower cover 13 respectively (see FIGS. 9
and 10). Alternatively, the first openings 31 are provided on a top of the upper cover
12 proximate two sides (see FIG. 11) and the first openings 31 are provided on a bottom
of the lower cover 13 proximate two sides (see FIG. 12). Thus, pressurized gas may
pass through one of the first openings 31 into the hollow body 11 to clockwise or
counterclockwise rotate the blade 22 about the drive shaft 21 prior to exiting from
the other first opening 31. As shown in FIG. 3 specifically, two opening members 118
are provided on the second arc surface 117 of the second part 112. When the first
openings 31 are provided on two sides of the upper cover 12 and the lower cover 13
respectively, one of the opening members 118 may communicate with one of the first
openings 31 via one of two channels 119 and the other opening member 118 may communicate
with the other first opening 31 via the other one of the channels 119 respectively,
and the first openings 31 are blocked from communicating with the external.
[0014] Referring to FIGS. 13 to 15, a pneumatic cylinder in accordance with a second preferred
embodiment of the invention is shown. The characteristics of the second preferred
embodiment are substantially the same as that of the first preferred embodiment except
the following: a gas compartment 40 can be connected to the housing 10 and communicates
therewith. In the second embodiment, the gas compartment 40 is integrally connected
to a side of the housing 10. The first openings 31 are provided on a top of the upper
cover 12 and a bottom of the lower cover 13 respectively. Pressurized gas may enter
one of the first openings 31 to clockwise or counterclockwise rotate the blade 22
about the drive shaft 21 prior to exiting from the other first opening 31. After finishing
the gas input, the pressurized gas in the gas compartment 40 may exert a reaction
force on the blade 22 to push the blade 22 to its original position.
[0015] Referring to FIG. 16, a pneumatic cylinder in accordance with a third preferred embodiment
of the invention is shown. The characteristics of the third preferred embodiment are
substantially the same as that of the second preferred embodiment except the following:
the gas compartment 40 is provided on a top of the upper cover 12. The gas compartment
40 communicates with the hollow body 11 via the upper cover 12. Alternatively, the
gas compartment 40 is provided on a bottom of the lower cover 13. The gas compartment
40 communicates with the hollow body 11 via the lower cover 13.
[0016] Referring to FIG. 17, a pneumatic cylinder in accordance with a fourth preferred
embodiment of the invention is shown. The characteristics of the fourth preferred
embodiment are substantially the same as that of the second preferred embodiment except
the following: the gas compartment 40 is separated from the housing 10 and communicates
with the housing 10 via a tube 32.
[0017] As shown in FIGS. 2-6, 15 and 16 specifically, an electromagnetic valve 50 is provided
at an end of the housing 10 or at an end of the gas compartment 40. The electromagnetic
valve 50 includes two second openings 51 communicating with the opening members 118
respectively. The electromagnetic valve 50 may control the flow of the pressurized
gas through one of the second openings 51 to clockwise or counterclockwise rotate
the blade 22 about the drive shaft 21. After finishing the gas input, the pressurized
gas in the gas compartment 40 may exert a reaction force on the blade 22 to push the
blade 22 to its original position.
[0018] The invention has the following advantages and benefits in comparison with the conventional
art: For increasing space of the housing 10, only length of the hollow body 11 is
changed and shapes and sizes of the upper cover 12 and the lower cover 13 are not
changed. Production is made easy. Manufacturing cost is decreased. It is applicable
to either fail-safe cylinder (FSC) or double-acting cylinder (DAC).
Reference numbers
[0019]
- 100
- pneumatic cylinder
- 10
- housing
- 11
- hollow body
- 12
- upper cover
- 13
- lower cover
- 111
- first part
- 112
- second part
- 113
- first compartment
- 114
- second compartment
- 14
- activation chamber
- 141
- first activation space
- 142
- second activation space
- 121
- first hole
- 131
- second hole
- 115
- first arc surface
- 116
- side surfaces
- 117
- second arc surface
- 20
- rotor
- 21
- drive shaft
- 22
- blade
- 221
- first section
- 222
- second section
- 23
- seal
- 15
- flat surface
- 31
- first openings
- 118
- opening members
- 119
- channels
- 40
- gas compartment
- 32
- tube
- 50
- electromagnetic valve
- 51
- second openings
1. A pneumatic cylinder,
characterized by comprising:
a housing (10) comprising a hollow body (11), an upper cover (12), and a lower cover
(13), the hollow body (11) including a first part (111) having a fan-shaped cross-section,
a second part (112) having a half circular section, a first compartment (113) on an
upper portion, and a second compartment (114) on a lower portion, the first compartment
(113) and the second compartment (114) communicating with each other and having the
same shape, the upper cover (12) and the lower cover (13) being disposed on the first
compartment (113) and the second compartment (114) respectively, thereby forming an
activation chamber (14) in the hollow body (11), the activation chamber (14) including
a first activation space (141) in the first part (111) and a second activation space
(142) in the second part (112), the first activation space (141) communicating with
the second activation space (142), the upper cover (12) including a first through
hole (121), and the lower cover (13) including a second through hole (131) aligned
with the first through hole (121);
a rotor (20) disposed in the activation chamber (14) and including a drive shaft (21)
having two ends rotatably disposed in the first through hole (121) and the second
through hole (131) respectively, and a blade (22) secured to the drive shaft (21),
the blade (22) being configured to rotate about the drive shaft (21) in the activation
chamber (14), the drive shaft (21) being configured to divide the blade (22) into
a first section (221) and a second section (222) having a length less than a length
of the first section (221) so that the first and second sections (221, 222) are not
symmetrical by the division of the drive shaft (21), the first section (221) is configured
to rotate in the first activation space (141), the second section (222) is configured
to rotate in the second activation space (142), and a plurality of segments are formed
on an inner surface of the hollow body (11) along an axial direction of the drive
shaft (21) and the segments have the same shape and size; and
two first openings (31) disposed on two sides of the housing (10) respectively so
that pressurized gas is configured to pass through one of the first openings (31)
into the hollow body (11) to clockwise or counterclockwise rotate the blade (22) about
the drive shaft (21) prior to exiting from the other first opening (31).
2. The pneumatic cylinder of claim 1, characterized in that the first openings (31) are disposed on two sides of the hollow body (11) respectively,
or the first openings (31) are disposed on one side of the upper cover (12) and one
side of the lower cover (13) respectively, or the first openings (31) are disposed
on a top of the upper cover (12) proximate two sides, or the first openings (31) are
disposed on a bottom of the lower cover (13) proximate two sides.
3. The pneumatic cylinder of claim 1 or 2, characterized in that the first openings (31) are disposed on two sides of the upper cover (12) and the
lower cover (13) respectively, the first openings (31) are blocked from communicating
with the external, and the second part (112) includes two opening members (118), one
of the opening members (118) may communicate with one of the first openings (31) via
one of two channels (119) and the other opening member (118) may communicate with
the other first opening (31) via the other one of the channels (119) respectively.
4. The pneumatic cylinder of claim 3, characterized by further comprising a gas compartment (40), the gas compartment (40) disposed on a
top of the upper cover (12), the gas compartment (40) being configured to communicate
with the hollow body (11) via the upper cover (12), or the gas compartment (40) disposed
on a bottom of the lower cover (13), the gas compartment (40) being configured to
communicate with the hollow body (11) via the lower cover (13).
5. The pneumatic cylinder of claim 4, characterized in that the gas compartment (40) is integrally connected to a side of the housing (10) or
separate from the housing (10) and being configured to communicate with the housing
(10) via a tube (32).
6. The pneumatic cylinder of claim 4 or 5, characterized by further comprising an electromagnetic valve (50) disposed at an end of the housing
(10) or at an end of the gas compartment (40), the electromagnetic valve (50) including
two second openings (51) communicating with the opening members (118) respectively.
7. The pneumatic cylinder of claim 5 or the alternative of claim 6 referring to claim
5, characterized by further comprising an electromagnetic valve (50) disposed at an end of the housing
(10) or at an end of the gas compartment (40), the electromagnetic valve (50) including
two second openings (51) communicating with the opening members (118) respectively.
8. The pneumatic cylinder of one of claims 3 to 7, characterized by further comprising an electromagnetic valve (50) disposed at an end of the housing
(10), the electromagnetic valve (50) including two second openings (51) communicating
with the opening members (118) respectively.
9. The pneumatic cylinder of one of the preceding claims, characterized by further comprising a flat surface (15) on a bottom of the upper cover (12) and on
a top of the lower cover (13) respectively, the flat surfaces (15) corresponding to
the rotor (20).
10. The pneumatic cylinder of one of the preceding claims, characterized in that the first part (111) includes a first arc surface (115) and two side surfaces (116)
integrally formed at two ends of the first arc surface (115) respectively, the second
part (112) includes a second arc surface (117) having a width less than a width of
the first arc surface (115), the first arc surface (115) is opposite to the second
arc surface (117), and the first and second arc surfaces (115, 117) are convex.
11. The pneumatic cylinder of one of the preceding claims , characterized in that the rotor (20) is disposed in the activation chamber (14) and is configured to rotate
an angle between 30-degree and 180-degree in the activation chamber (14).
12. The pneumatic cylinder of one of the preceding claims , characterized by further comprising a seal (23) disposed around the blade (22) to prevent pressurized
gas from leaking.