Note: Descriptions are shown in the official language in which they were submitted.
TITLE: COMBINATION HYDRAULIC AND PNEUMATIC DOOR CLOSER
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application 14/795,004
filed July
9, 2015, which in turn claims priority to Chinese Application No. CN
201510318849.8
having a filing date of June 11, 2015.
FIELD OF TECHNOLOGY
The following relates to the field of door closers, in particular a door
closer
capable of adjusting its closing speed.
BACKGROUND OF THE INVENTION
The closing speed of a door closer is usually controlled by controlling the
flow
velocity of oil therein. However, the viscosity of oil varies upon changing
temperature, to
affect the closing speed of door closers greatly in the regions having big
diurnal
temperature amplitude, e.g. North America and the North China. It can be known
from the
experiments, the closing time of a hydraulic door closer is about 8 seconds at
25 C, the
closing time is increased to about 2 minutes, which is 15 times the former. A
much longer
closing time can cause many problems, for example, the cold air in winter can
enter the
house easily, or a security flaw will appear. Moreover, it is difficult for
users to adjust the
door closer, the above flaws should increase the maintenance service cost and
may incur a
risk of oil spilling.
Accordingly, a primary objective of the present invention is the provision of
an
improved door closer.
Another objective of the present invention is the provision of a door closer
having
both a pneumatic cylinder and a hydraulic cylinder.
Another objective of the present invention is the provision of a door closer
having
dual hydraulic and pneumatic functions.
A further objective of the present invention is the provision of an improved
door
closer, which overcomes the problems of the prior art.
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Yes another objective of the present invention is the provision of a door
closer
which is economical to manufacture, and durable and safe in use.
These and other objectives have become apparent from the following description
of
the invention.
SUMMARY OF THE INVENTION
A door closer according to the present invention has an adjustable closing
speed,
which is less influenced by temperature, and has a constant closing speed.
The door closer according to embodiments of the invention, comprises a
pneumatic
cylinder on the door frame, a hydraulic cylinder on the door, and a lever; one
end of the
lever is movably connected to the pneumatic cylinder, and the other end is
connected to the
hydraulic cylinder.
The pneumatic cylinder comprises a housing arranged on the door frame, and a
sliding member within the housing. A hermetic chamber is formed at one end of
the
housing. An adjustable valve, for adjusting the exhaust of the hermetic
chamber, is
provided on the hermetic chamber. The lever is pivotally attached to the
sliding member.
The hydraulic cylinder comprises a housing on the door, a spring in the
housing, a
piston and 9 cam follower or roller connected to the spring, and a rotatable
cam for
transferring the spring energy to the roller. The lever is fixedly connected
to the cam.
Furthermore, the sliding member comprises a sliding block, a piston and a
joint rod
for connecting the sliding block and the piston.
Furthermore, the sliding member includes a piston having a periphery groove, a
seal ring movably configured in the groove, and an air intake or passageway
through the
sliding member.
More particularly, the piston has a first side wall and a second side wall are
formed
at the groove, wherein the first side wall is adjacent to the hermetic chamber
while the
second side wall is opposite the first side wall. A first air intake is
configured on the first
side wall.
A gap is provided between the second side wall and an inner side wall of the
sliding
rail. The second side wall is inclined from the bottom of the groove, such
that air enters
the hermetic chamber through the first air intake and the gap when the piston
slides
towards door hinge, such that the air in the hermetic chamber is then
compressed and the
seal ring seals the gap, and thereby the air can be exhausted only by a
regulating valve at
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the opposite end of the cylinder. Therefore, the counteraction to the piston
can be adjusted
by adjusting the exhaust of the regulating valve, and thereby the sliding
speed of the
sliding block can be adjusted.
In the preferred embodiment, the elastic component is a spring, and the pulley
is a
cam. The driving components comprises a driving piston configured at one end
of the
spring, and a cam roller on the driving piston. The cam roller is tangent to
the profile of
the cam. The intersection of the cam roller and the cam deviates from a line
through the
center of the cam roller to the shaft of the cam. The other end of the spring
is connected
with the side wall of the receiving chamber. The profile of the cam is
designed to balance
the varied resilience of the spring, such that the door is closed uniformly.
Further, in order
to close the door eventually, the spring ensures that there is a sufficient
thrust to close the
door fully.
In an alternative embodiment, the pulley is a gear, and the driving component
is a
rack engaged with the gear. The rack is connected to one end of the spring,
and the other
end of the spring is connected with a side wall of the receiving chamber.
Preferrably the hydraulic cylinder is configured on the door, and with the
driving
apparatus positioned within the cylinder chamber.
Furthermore, the adjusting member is a regulating valve, for convenience.
Furthermore, the sliding rail is a pneumatic cylinder. The regulating valve is
configured on one end of the hermetic chamber, of this cylinder, and a vent is
configured
on the other end of the hermetic chamber. A slot for the lever is arranged on
the cylinder.
For aesthetics purpose, the pneumatic gas adjusting apparatus is embedded into
the
beam of the door frame, and the hydraulic cylinder housing is embedded into
the top of the
door.
Compared with the prior art, the beneficial effects are
(1) The hermetic chamber is formed by the piston and the cylinder, such that
the
sliding speed of the sliding block, and further the closing speed of the door,
can be
controlled by adjusting the regulating valve. As the air flow is insensitive
to air
temperature, the closing speed of the door can be constant whatever the air
temperature varies. Thus, the regulating valve can be adjusted when the door
closer is installed, for constant reliability and operation.
(2) The driving structure is formed by the cam and the spring. When the door
starts
closing, the spring possesses a great resilience, but when the door is almost
closed
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completely, the spring possesses a small resilience. The closing force can be
adjusted by the profile of the cam as the resilience of the spring is varied
all the
way, thus the door is closed at a uniform speed. In addition, the cam can
ensure
there is a sufficient thrust to the door being locked eventually, and
eliminates the
risk of hitting people passing through the door.
(3) The use of air for controlling door closing reduces the cost and the
maintenance
service fee, and eliminates the contamination of hydraulic fluid.
Figure 6 is an enlarged view of the regulating value in a partially closed
position.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will be further described in
detail
hereinafter with reference to the accompanying drawings.
Figure 1 is a structural view of the door closer of the present invention,
which is
capable of adjusting its closing speed when the door is open at the angle of
90 degrees.
Figure 2 is a structural view of the door closer capable of adjusting the
closing
speed when the door is open at the angle of 450.
Figure 3A is an enlarged partial view of the pneumatic cylinder of the door
closer
during opening of the door, taken along line A of Figure 1.
Figure 3B is a partial enlarged view of section B of Figure 2, during closing
of the
door.
Figure 4A is an enlarged view of the regulating valve in a substantially
closed
position, taken along line C of Figure 1.
Figure 413 is a view similar to Figure 4A with the regulating valve in
substantially
open position.
Figure 5 is a sectional view of the hydraulic cylinder when the door is in an
enclosed position.
Figure 6 is a sectional view of the hydraulic cylinder when the door is in an
open
position.
Figure 7 is a sectional view of the hydraulic cylinder showing the fluid flow
path
when the door is opening, with some components on parts removed for clarity.
Figure 8 is a sectional view of the hydraulic cylinder, similar to Figure 7,
showing
the fluid flow path when the door is closing.
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Figure 9 is another sectional view of the hydraulic cylinder showing the fluid
flow
path when the door is closing.
Figure 10 is sketch showing the dual door closer of the present invention on a
door
and a door frame.
Figure 11 is a view of a second embodiment of the door closer capable of
adjusting
its closing speed.
REFERENCE LIST
¨ door frame
12 ¨ door
10 14 ¨ pneumatic cylinder
16 housing
18 ¨ receiving chamber
¨ driving component/hydraulic cylinder
20A ¨ rack and pinion cylinder
15 22 ¨ lever
24 ¨ sliding block
26 ¨joint rod
28 ¨ piston
¨ hermetic chamber
20 32 ¨ regulating valve
34 ¨ vent
36 ¨ groove
38 ¨ seal ring
¨ first side wall
25 42 ¨ second side wall
44 ¨ first air intake
¨ gap
46 ¨ cam
48 ¨ spring
30 .. 50 ¨ driving piston
52 ¨ cam roller
53 gear
54 ¨ rack
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56 - contact point
58 ¨ center line
60 ¨ piston movement for door opening
62 ¨ ball valve
63 ¨ hole in piston
64 ¨ return passage
66 ¨ piston movement for door closing
68 ¨ oil flow path for door closing
69 ¨ return passage
70 ¨ regulating valve
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will be further described in detail
hereinafter with reference to the accompanying drawing. However, it should be
understood that the preferred embodiments herein are only described for
explaining the
present invention, and the invention is not limited to the embodiments
described herein.
Embodiment 1
As shown in the figures a door closer mounted on or in a door frame 10 and a
door
12. The closer 10 is capable of adjusting its closing speed, and comprises a
pneumatic
cylinder 14 mounted in the door frame 10, and a hydraulic cylinder 16 mounted
in the door
12. A receiving chamber 18 is formed inside the cylinder 16. A driving
apparatus 20 is
mounted in the receiving chamber 18. A lever 22 connects the gas adjusting
apparatus 24,
26, 28 and the driving apparatus 20.
A gas adjusting apparatus 24, 26, 28 is provided inside the pneumatic cylinder
14,
and comprises a sliding block 24, a piston 28 and a joining rod 26 for
connecting the
sliding block 24 and the piston 28. A hermetic chamber 30 is formed by the
piston 28 at
one end of the cylinder 14. A regulating valve 32, for adjusting the exhaust
velocity of the
hermetic chamber 30, is threadably mounted in the wall of the hermetic chamber
30 at one
end of the pneumatic cylinder 14. The other end of the cylinder 14 opposite
the heimetic
chamber 30 is provided with a vent 24.
The piston 28 has an air passageway comprising a groove 36 on the periphery of
the piston 28, and a seal ring 38 movably configured in the groove 36. The
groove 36 has
a first side wall 40 and a second side wall 42 is opposite the wall 40. A
first air intake 44
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extends from the first side wall 40 to the chamber 30. There is a gap 45
between the
second side wall 42 and the inner side wall of the cylinder 14. The first side
wall 40 is in a
plane perpendicular to the direction of movement of the piston 28, while the
second side
wall 42 is an inclined plane from bottom of the groove 36.
The driving apparatus comprises a cam 46, a spring 48 and driving components
20,
inside the chamber 18 of the hydraulic cylinder 16. The driving components 20
comprise a
driving piston 50 and a cam roller 52 configured on the driving piston 50. One
end of a
spring 48 is connected to an end of the chamber 18 while the other spring end
is connected
to the driving piston 50. The intersection of the cam roller 52 and the cam 46
deviates
from a line from the center of the cam roller 52 to the shaft of the cam 46.
One end of the lever 22 is hinged to the sliding block 24, while the other end
of the
lever 22 is fixed to the shaft of the cam 46.
The pneumatic cylinder 14 is embedded into the beam of the door frame 10, and
the
hydraulic cylinder 16 is embedded into the top of the door 12. However, the
cylinders 14
and 16 of embodiments of the present invention is not limited to such
positions, and may
be configured at the bottom of the door frame and the door instead, upon
actual
requirement. The cylinders 14 and 16 may also be mounted to the exterior of
the door
frame 10 and the door 12. The cylinders 14 and 16 may also be reversed such
that cylinder
14 is on or in the door 12 and the cylinder 16 is on or in the door frame 10.
The cylinder 14 is used as a guide rail for the sliding block 24, however,
this is not
a limitation to embodiments of the present invention. Alternatively, the
cylinder 14 can be
formed in two parts, wherein one part would be a hermetic cylinder for
installing the piston
28, while the other part would be an open guide rail to cooperate with the
sliding block 24.
The sliding members in the assembly are the sliding block 24 and the piston
28,
which are connected together by the joint rod 26, however, this is not a
limitation to
embodiments of the present invention. Alternatively, the sliding block 24 and
the piston
28 could be integrated together inside the cylinder 14.
The operation of the door closer of the present invention is as follows:
When the door 12 is opened manually, the door 12 drives the sliding block 24
sliding towards left side in Figure 1 through the lever 22, then the sliding
block 24 brings
the piston 28 sliding towards left side through the joint rod 26, so that air
enters the
hermetic chamber 30 through the gap 45 and the first air intake 44. Meanwhile
the lever
22 drives the cam 46 to rotate about its axle. The cam 46 drives the cam
roller 52 to
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compress the spring 48. When the door 12 is released, the spring 48
decompresses and
drives the cam roller 52, which in turn drives the cam 46 rotating about its
axle.
Simultaneously, the sliding block 24 is driven by the lever 22 and slides
towards
right side in Figure 1, while the piston 28 is driven by the joint rod 26 and
slides towards
.. right side to compress the air in the hermetic chamber 30, whereby the air
in the hermetic
chamber 30 counteracts the movement of the piston 28, and the seal ring 38 is
forced to
contact with the second side wall 42 and seals the gap 45, such that the air
in the hermetic
chamber 30 can only be exhausted through the regulating valve 32. The
counteraction
force to the piston 28 can be adjusted by adjusting the exhaust of the
regulating valve 32,
and accordingly, the sliding speed of the sliding block 24 and the closing
speed of the door
is adjusted. When the door 12 starts closing, the spring 48 possesses a great
resilience and
can provide a great pushing force, but when the door almost closes completely,
the spring
48 possesses a small resilience and only provides a little pushing force to
the cam 46.
Therefore, the profile of the cam 46 may be designed to balance the resilience
variation of
the spring. When the door 12 starts closing, the intersection of the cam
roller and the cam
is designed to be adjacent to the straight line from the shaft of the cam 46
to the center of
the cam roller 52 as close as possible, and when the door 12 almost closes
completely, the
intersection is away from the straight line, whereby the closing speed of the
door is almost
uniform. In addition, the cam and cam roller ensure there is a sufficient
thrust to the door
12 being locked eventually.
The airflow for the pneumatic cylinder 14 is shown in Figures 3A, 3B, 4A, and
4B.
When the door 12 is opening, the piston 4 slides to the left, as seen in
Figure A and as
designated by the heavy arrow. This movement of the piston 28 forces air
through the gap
45 and into the chamber 30, as seen by the light arrows in Figure 3A. As the
door 12
closes, the piston 28 slides to the right within the cylinder 14, as
represented by the dark
arrow in Figure 3B. The seal 38 presents air from flowing backwards through
the gap 45.
As the door closes, the piston compresses the air into chamber 30, which is
exhausted or
expelled out of the chamber 30, as indicated by the arrow in Figure 4B.
Threading the
valve 32 into or out of the end of the cylinder 14 regulates the volume of the
air that can be
exhausted from the cylinder 14 as the door closes.
The flow of fluid in the hydraulic cylinder 20 as the door opens and closes is
shown
in Figure 7-9. More particularly, as the door opens, the piston 28 slides to
the right, as
indicated by the dark arrow in the passageway black, and past the ball valve.
Shown in
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Figure 8, when the door closes, the piston 50 moves to the left, as indicated
by the heavy
arrow, and follows the path of the broken arrow back to the chamber 18 of the
cylinder 20.
A second regulated valve in the cylinder 20 controls the rate in which the
fluid flows back
into the chamber 18.
Embodiment 2
As shown in Figure 1, the structure and work principle in this embodiment are
identical to those in Embodiment 1, except for the driving components. In this
alternative
embodiment, the pulley is a gear 53 and the driving component is a rack 54
engaged with
the gear 53. One end of the rack 54 is connected to the spring 48. One end of
the lever 22
is hinged to the sliding block 24 while the other end is fixed to the shaft of
the gear 53.
When the door is open, the lever 22 rotates the gear 53, which drives the rack
54
towards the spring 48, thereby the spring 48 possesses a great resilience.
When the door
12 is released, the spring 48 drives the rack 54, which rotates the gear 53,
such that the
lever 22 drives the sliding block 24 towards right side in Figure 7, whereby
the door 12 can
close automatically. The counteraction to the piston 28 can be adjusted by
adjusting the
exhaust of the regulating valve 12, and thereby the closing speed of the door
12 is adjusted.
In embodiments of the present invention, the hermetic chamber is formed by the
piston and the pneumatic cylinder 14, such that the sliding speed of the
sliding block, and
further the closing speed of the door, can be controlled by adjusting the
regulating valve
32. As the air flow is insensitive to air temperature, the closing speed of
the door 12 can
be constant whatever the air temperature varies. Thus the regulating valve 32
long can be
adjusted when the door closer is installed, for consistent and reliable use
all year. Such a
door closer reduces the cost and eliminates the contamination hydraulic of oil
spilling.
The other structure of the door closer in the embodiments may refer to known
door
closers.
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