U.S. patent application number 13/884824 was filed with the patent office on 2013-09-12 for high speed smart material actuator with second stage.
This patent application is currently assigned to Viking AT, LLC. The applicant listed for this patent is Jeffery B. Moler. Invention is credited to Jeffery B. Moler.
Application Number | 20130234561 13/884824 |
Document ID | / |
Family ID | 46207770 |
Filed Date | 2013-09-12 |
United States Patent
Application |
20130234561 |
Kind Code |
A1 |
Moler; Jeffery B. |
September 12, 2013 |
High Speed Smart Material Actuator with Second Stage
Abstract
A smart material actuator apparatus having a smart material
device, compensator, movable supporting member, two mechanical
webs, two actuating arms, and a second stage assembly. Application
of an electrical potential causes the smart material device to
expand, thereby moving the actuating arms. That movement causes
resilient strips to urge a second stage attachment surface in a
direction substantially parallel to the smart material device.
Optional dampening assemblies may be added where high speed
operation is desired, and an optional valve assembly may be
attached where an actuated valve, such as a high speed actuated air
valve, is needed.
Inventors: |
Moler; Jeffery B.;
(Sarasota, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Moler; Jeffery B. |
Sarasota |
FL |
US |
|
|
Assignee: |
Viking AT, LLC
Sarasota
FL
|
Family ID: |
46207770 |
Appl. No.: |
13/884824 |
Filed: |
December 9, 2011 |
PCT Filed: |
December 9, 2011 |
PCT NO: |
PCT/US11/64229 |
371 Date: |
May 10, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61421504 |
Dec 9, 2010 |
|
|
|
Current U.S.
Class: |
310/328 |
Current CPC
Class: |
H02N 2/043 20130101;
H01L 41/053 20130101 |
Class at
Publication: |
310/328 |
International
Class: |
H01L 41/053 20060101
H01L041/053 |
Claims
1. An actuator apparatus comprising a smart material device, a
compensator, a movable supporting member, two mechanical webs, two
actuating arms, and a second stage assembly wherein (a) said
mechanical webs comprise a first resilient member operably attached
to said compensator and a second resilient member attached to said
movable supporting member (b) said movable supporting member
comprises a first mounting surface, (c) said smart material device
is affixed between said first mounting surface and said
compensator; (d) said actuating arms comprise a first actuating arm
end attached to one said mechanical web and an opposed second
actuating arm end attached to said second stage assembly; and (e)
said second stage assembly comprises resilient strips having a
first resilient strip end attached to said second actuating arm end
and a second resilient strip end operably connected to a second
stage attachment surface wherein application of an electrical
potential causes said smart material device to expand, thereby
urging said movable supporting member away from said compensator
and causing said first and second resilient members to flex,
thereby moving said actuating arms and causing said resilient
strips to urge said second stage attachment surface in a direction
substantially parallel to said smart material device.
2. The actuator apparatus of claim 1 wherein said resilient strips
are formed of a material selected from the group consisting of
steel, spring steel, carbon fiber, fiberglass, plastic, stainless
steel, and aluminum.
3. The actuator apparatus of claim 1 wherein said second stage
attachment surface is formed of a material selected from the group
consisting of carbon fiber, steel, spring steel, fiberglass,
plastic, stainless steel, and aluminum.
4. The actuator apparatus of claim 1 further comprising at least
one dampener attached to said compensator and movably attached to
at least one said actuating arm, said dampener comprising a pliable
stop between said actuating arm and said compensator.
5. The actuator apparatus of claim 1 further comprising an outer
frame, said outer frame comprising an inner dampening stop and an
outer dampening stop for each said actuating arm wherein said outer
dampening stop is adapted to prevent said actuating arm from
overextending in the outward direction and said inner dampening
stop is adapted to prevent said actuating arm from overextending in
the inward direction.
6. The actuator apparatus of claim 1 wherein said resilient strips
are integral with said second stage attachment surface.
7. The actuator apparatus of claim 1 wherein said second resilient
strip ends are attached to said second stage attachment
surface.
8. The actuator apparatus of claim 1 further comprising a valve
assembly attached to said compensator, said valve assembly
comprising an inlet, an outlet, and a valve in between said inlet
and said outlet, and a valve stem operably connected to said valve
and to said second stage attachment surface wherein movement of
said second stage attachment surface causes said valve stem to
operate said valve.
9. The actuator apparatus of claim 8 wherein said valve assembly is
an air valve.
10. The actuator apparatus of claim 9 further comprising two
dampeners attached to said compensator and movably attached to each
said actuating arm, said dampeners comprising two pliable stops,
one said pliable stop being positioned between said actuating arms
and said compensator.
11. The actuator apparatus of claim 1 wherein said resilient strips
extend away from said second actuating arm ends such that movement
of said second actuating arm ends toward said smart material device
urges said second stage attachment surface away from said
compensator.
12. The actuator apparatus of claim 1 wherein said resilient strips
extend toward said compensator such that movement of said second
actuating arm ends toward said smart material device urges said
second stage attachment surface toward said compensator.
13. The actuator apparatus of claim 1 wherein said actuating arms
extend toward said compensator.
14. The actuator apparatus of claim 1 wherein said actuating arms
extend away from said compensator.
15. The actuator apparatus of claim 1 wherein said compensator is
integral with said mechanical webs.
16. The actuator apparatus of claim 1 wherein said compensator is
mechanically attached to said mechanical webs.
Description
BACKGROUND
[0001] This application claims priority to provisional application
No. 61/421,504 filed Dec. 9, 2010, which is incorporated herein in
its entirety.
[0002] The present invention relates to a smart material actuator
apparatus adapted to operate at high speed and incorporating a
second stage assembly adapted to translate inward or outward
movement of the actuating arms to linear movement of a second stage
centerpiece.
[0003] Certain smart material actuators are known in the art. Such
actuators, however, are not adapted to high speed operation for
reasons including lower than desirable resonant frequencies and
rebound effects. Additionally, prior art smart material actuators
are either direct-acting (meaning that the smart material device
itself actuates the component to be actuated), or mechanically
amplified (meaning mechanical webs or other mechanical
amplification means is utilized to increase the stroke length so
that it is greater than the expansion of smart material device
itself). Where mechanical amplification was utilized, however, the
resulting motion was not in the same direction as the direction of
expansion of the smart material device.
[0004] The present invention addresses those concerns by providing
a mechanically amplified smart material actuator apparatus,
embodiments of which are capable of operation at very high speeds,
and in which the direction of actuation is substantially parallel
to the expansion of the smart material. Such actuators are
desirable in a variety of applications including, without
limitation, in sorting machines in which a stream of material is
passed through a passageway with a sensor adapted to detect faulty
particles as they pass. An air valve is then activated to expel the
faulty particle from the stream as it passes. Allowing for the air
valve to be activated and deactivated at higher speeds allows
greater throughput through the passage. Accordingly, a higher
speed, mechanically amplified smart material actuator according to
the present invention is well suited for such applications as it
allows for both high speed operation and a convenient configuration
as the direction of actuation is substantially parallel with the
smart material itself.
[0005] This application hereby incorporates by reference, in their
entirety, provisional applications Nos. 61/551,530, 61/452,856,
61/504,174 as well as PCT/US2010/041727, PCT/US10/041461,
PCT/US2010/47931, PCT/US2011/25292, PCT/US2011/25299, U.S. patent
application Ser. Nos. 13/203,737, 13/203,729, 13/203,743 and
13/203,345, and U.S. Patents:
[0006] U.S. Pat. No. 6,717,332;
[0007] U.S. Pat. No. 6,548,938;
[0008] U.S. Pat. No. 6,737,788;
[0009] U.S. Pat. No. 6,836,056;
[0010] U.S. Pat. No. 6,879,087;
[0011] U.S. Pat. No. 6,759,790;
[0012] U.S. Pat. No. 7,132,781;
[0013] U.S. Pat. No. 7,126,259;
[0014] U.S. Pat. No. 6,924,586
[0015] U.S. Pat. No. 6,870,305;
SUMMARY
[0016] The present invention discloses an actuator apparatus
comprising a smart material device, a compensator, a movable
supporting member, two mechanical webs, two actuating arms, and a
second stage assembly. The mechanical webs comprise a first
resilient member operably attached to the compensator and a second
resilient member attached to the movable supporting member. The
movable supporting member comprises a first mounting surface and
the smart material device is affixed between the first mounting
surface and the compensator, with the optional inclusion of a
spacer. The actuating arms comprise a first actuating arm end
attached to one mechanical web and an opposed second actuating arm
end attached to the second stage assembly. The second stage
assembly comprises resilient strips having a first resilient strip
end attached to the second actuating arm end and a second resilient
strip end operably connected to a second stage attachment surface.
Application of an electrical potential causes the smart material
device to expand, thereby urging the movable supporting member away
from the compensator and causing the first and second resilient
members to flex, thereby moving the actuating arms. That movement
causes the resilient strips to urge the second stage attachment
surface in a direction substantially parallel to the smart material
device. Optional dampening assemblies may be added where high speed
operation is desired, and an optional valve assembly may be
attached where an actuated valve is needed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Other features in the invention will become apparent from
the attached drawings, which illustrate certain preferred
embodiments of the apparatus of this invention, wherein
[0018] FIG. 1 is a front, sectional view of a preferred embodiment
of the actuator assembly of the apparatus of the present
invention;
[0019] FIG. 2 is a perspective view of the embodiment shown in FIG.
1;
[0020] FIG. 3 is a front, sectional view of the embodiment shown in
FIG. 1 adapted to operate an air valve assembly;
[0021] FIG. 4 is a detailed sectional view of the dampener assembly
utilized in the embodiment illustrated in FIG. 1;
[0022] FIG. 5 is a graph showing oscillation of an actuator
assembly of the present invention without dampener assemblies
installed;
[0023] FIG. 6 is a graph showing oscillation an actuator assembly
of the present invention with dampener assemblies installed;
[0024] FIG. 7 is a front view of an embodiment of an actuator
assembly of the present invention having an external case (shown
sectionally) with integrated dampeners and adapted to operate an
air valve assembly;
[0025] FIG. 8 is a detail, perspective view of the attachment
between the actuator assembly and the air valve assembly in the
embodiment illustrated in FIG. 7; and
[0026] FIG. 9 is a front view of a preferred embodiment of an
actuator assembly according to the present invention having
reversed actuating arms, a reversed one-piece second stage
assembly, and no dampener assemblies.
DETAILED DESCRIPTION
[0027] While the following describes preferred embodiments of this
invention, it is understood that this description is to be
considered only as illustrative of the principles of the invention
and is not to be limitative thereof, as numerous other variations,
all within the scope of the invention, will readily occur to
others.
[0028] It will be noted that in the illustrated embodiments,
different embodiments comprise the same or similar components. This
is preferred as it reduces manufacturing and repair costs by
allowing for use of interchangeable parts, and also allows for
assembly of a broader variety of actuator assemblies. Where the
same component is suitable for use in different embodiments, the
same reference number is used. For example, and without limitation,
actuating arm 114 is illustrated as a common component that may be
used in embodiments including 100, 400 and 500. Accordingly, the
same number is used to indicate the common part used in the
illustration of each. Where components in different embodiments
have a similar structure, but are not necessarily common parts, a
prime is used. For example, and without limitation, attachable
compensator 103 serves the same function as integral compensator
103'. Although similar, compensators 103 and 103' are
distinguishable in that one is attachable and the other is a
portion of an integrated component. Accordingly, the same element
number is utilized with prime notation to indicate distinct
variations.
[0029] Herein, the following terms shall have the following
meanings:
[0030] The term "adapted" shall mean sized, shaped, configured,
dimensioned, oriented and arranged as appropriate.
[0031] The term "smart material device" shall mean a device
comprising a material that expands when an electric potential is
applied or generates an electric charge when mechanical force is
applied. Smart material devices include, without limitation,
devices formed of alternating layers of ceramic piezoelectric
material fired together (a so-called co-fired multilayer ceramic
piezoelectric stack such as those available from suppliers
including NEC) or a device formed of one or more layers of material
cut from single crystal piezoelectric materials. In the foregoing,
the term "piezoelectric material" also includes so-called "smart
materials," sometimes created by doping known piezoelectric
materials to change their electrical or mechanical properties.
[0032] The term "mechanical web" shall mean a structure comprising
at least two resilient members and being adapted to translate
motion to an actuating arm. Motion is translated by applying a
force that causes the resilient members to flex. The resilient
nature of the resilient members, however, indicates that they will
return to substantially their original configuration upon removal
of that force. There are a wide variety of materials that may be
used to form resilient members, including, without limitation,
steel, stainless steel, aluminum, carbon fiber, plastic and
fiberglass.
[0033] The term "activation" when used in conjunction with
"actuator" or "smart material device" means application of an
electrical potential and current suitable to cause the smart
material device to expand in an amount sufficient to flex the
compliant members of at least one mechanical web of the actuator
apparatus.
[0034] The term "valve stem" means any structure capable of
operating a valve mechanism including without limitation the axial
rod attached to a poppet valve or any spool, diaphragm or similar
or related structure capable of operating a valve. In the context
of the current invention, an actuated valve is opened and/or closed
when an actuator applies force to a valve stem.
[0035] The definitions and meanings of other terms herein shall be
apparent from the following description, the figures, and the
context in which the terms are used.
[0036] The task of designing an actuator, smart material or
otherwise, that is capable of operating at high speed, including
speeds in the range of 500 to 5,000 operations per second, presents
numerous challenges. One such challenge is that the actuator may
resonate at high operational speeds as is further described in the
incorporated references. A second challenge is that operation at
speed may cause the moving components of the actuator to
over-extend or over-rebound or fatigue prematurely.
[0037] Embodiments of the present invention address these
challenges by providing a smart material actuator capable of
sustained high speed operation, a preferred embodiment of which is
suitable for operation of a high speed air valve. The combination
of actuator and air valve is adapted for operation in a sorting
machine in which air pressure is used to eject defective items from
a stream and requires operational speeds in the range of 0 to 1,200
bursts per second. As will be understood by those of skill in the
art, however, there are myriad applications for actuators adapted
to operate at high speed and the present invention shall not be
limited to the specific embodiments or applications herein
described.
[0038] The task of designing a smart material actuator also
presents challenges with respect to the degree and direction of
motion achieved. If the action of the smart material that provides
the motive force is not amplified, only a limited stroke can be
achieved. For applications requiring a longer stroke, mechanical
amplification may be used (as is also described in the incorporated
references). Such designs, however, tend to produce motion that is
orthogonal to, or at a non-zero angle with respect to, the motion
of the smart material device. It is sometimes more convenient to
have amplified motion in the same direction as the expansion of the
smart material device itself.
[0039] Referring to the figures, FIG. 1 illustrates a cut-away view
of an embodiment of the actuator apparatus of the present invention
with FIG. 2 illustrating a perspective view of the embodiment in
FIG. 1 in solid form, but without smart material device 102
installed. In the illustrated embodiment, actuator assembly 100
comprises second stage assembly 180 attached to actuating arms 114.
A smart material device 102 is situated within compensator 103
between first mounting surface 108 and optional spacer 106. Smart
material device 102 comprises electrode 104 which may conveniently
extend through first mounting surface 108. Compensator 103 acts as
a fixed supporting member such that substantially upon application
of an appropriate electrical potential smart material device 102
expands, urging first mounting surface 108 on movable supporting
member 109 away from compensator 103. As movable supporting member
109 moves, first resilient member 110 and second resilient member
111 of mechanicals webs 113 flex, thereby moving actuating arms
114. In the embodiments illustrated, second actuating arm ends 116
move toward smart material device 102. Mechanical webs 113 may
suitably be constructed from stainless steel or another material
with sufficient strength and resilience, as is discussed further in
the incorporated references. Compensator 103 may be constructed of
any suitably rigid material (such as without limitation carbon
fiber, steel, aluminum, or stainless steel) and may be operably
attached to first resilient members 110 by mechanical connection as
illustrated, or by making compensator 103' integral to mechanical
webs 113 such that they are formed as a single part (see FIG. 7).
Where high speed operation is desired, actuating arms 114, however,
are preferably formed of a lighter weight material such as carbon
fiber, and may be attached to mechanical webs 113 with mechanical
fasteners 112 which may conveniently be machine screws. Lighter
weight actuating arms 114 are preferred where high speed operation
is needed as they increase the resonant frequency of the actuator
apparatus 100, as is discussed further in the incorporated
references. In applications in which the frequency of actuation is
not necessarily constant, such as the sorting machine application
described above, it is desirable that the resonance frequency be
higher than the maximum expected frequency of actuation. Otherwise
resonance effects could cause excessive flexing of first resilient
members 110 and second resilient members 111 and/or other damaging
effects, thereby limiting the working life of the assembly. While
carbon fiber is a convenient material to use for actuating arms 114
as it is both strong and light in weight, thereby assisting in
efforts to increase the resonant frequency of the assembly, other
materials may also be used including, without limitation aluminum,
steel, stainless steel, fiberglass and plastic. The weight of
actuating arms 114 may also be lessened through the use of hollow
or u-shaped designs such as those described in the incorporated
references.
[0040] Actuating arms 114 are connected to second stage assembly
180. Second stage assembly 180 converts the motion of second
actuating arm ends 116 to a substantially linear movement
substantially parallel to the direction of expansion of smart
material device 102. Second stage assembly 180 comprises resilient
strips 182 which may conveniently be strips of steel, spring steel,
carbon fiber, fiberglass, plastic, stainless steel or aluminum.
First resilient strip end 181 attaches to second actuating arm end
116. This may be accomplished with any variety of mechanical or
adhesive connection, including the use of pins 183 that pass
through first resilient strip end 181 as shown in the figure.
[0041] Second resilient strip ends 185 are operably connected to
second stage attachment surface 184. This may also be accomplished
with any variety of mechanical or adhesive connection, including
the use of pins 187 that pass through second resilient strip end
185 as shown in the figure. Second stage attachment surface 184 may
conveniently be a block formed of carbon fiber, steel, spring
steel, fiberglass, plastic, stainless steel or aluminum, and
comprises a means 186 to connect to an apparatus to be actuated. As
illustrated, means 186 is a hole suitable for receiving a valve
stem (not illustrated) as is further described below. Other means
may also be utilized including any suitable combination of
mechanical fasteners or clamps, or adhesives, as will be readily
understood by those of ordinary skill in the art. In this way, when
actuating arms 114 move inward, resilient strips 182 urge second
stage attachment surface 184 in a direction substantially parallel
to smart material device 102. When actuating arms 114 return back
outward, resilient strips 182 urge second stage attachment surface
184 back toward its original position. Where high speed operation
is required, second stage attachment surface 184 is also preferably
formed of a light weight material such as carbon fiber, which helps
increase the resonant frequency of the apparatus.
[0042] Actuator assembly 100 further comprises dampener assemblies
150, which are shown in greater detail in FIG. 4. Dampener
assemblies 150 are preferred for high speed operation as they both
act to prevent over extension of actuating arms 114 and also serve
to dampen ringing which can, in certain circumstances, damage the
actuator assembly or limit the maximum operational frequency.
Referring to FIG. 4, dampener assemblies 150 comprise set screw 152
which passes through outer pliable stop 154, through actuating arm
114, through inner pliable stop 156, which is situated between
actuating arm 114 and compensator 103, and into compensator 103.
The passage through actuating arm 114 is adapted to allow free
movement of actuating arm 114 about dampener assembly 150, while
the head of set screw 152 and outer pliable stop 154 are adapted to
resist over-extension of actuating arm 114. In this way dampener
assemblies 150 can be attached to compensator 103 (preferably
through a threaded or welded connection) and movably attached to
actuating arms 114. Stopper nuts 158 serve both to position and
secure inner pliable stop 156 and to secure set screw 152 to
compensator 103. By tightening stopper nuts 158 against each other
and against compensator 153, unwanted loosening and tightening of
set screw 152 and unwanted movement of inner compliant stop 156 can
be minimized.
[0043] During operation, actuating arms 114 move between inner
pliable stop 156 and outer pliable stop 154. At the intended
movement limits, inner pliable stop 156 and outer pliable stop 154
are impacted by actuating arm 114 and will preferably yield to
absorb shock. Accordingly, inner pliable stop 154 and outer pliable
stop 156 may conveniently be formed of a compliant but resilient
material such as Buna rubber or other similar materials known in
the art. The result is that actuating arms 114 are prevented from
over-extension in either direction and vibrations created by the
impact of actuating arms 114 at either end of their movement range
are dampened.
[0044] As has been discussed, for high speed operation, it is
desirable to have an actuator assembly 100 with a high resonant
frequency. It is also desirable to reduce ringing. The change in
momentum when the actuating arms 114 are moving quickly with the
rapid expansion of smart material device 102, and then suddenly
stopped, can be very rapid. The natural spring tendencies of the
assembly can cause spring force in the return direction, thereby
promoting a dampening oscillation back and forth, as well as
potential overshooting. This is in part because the momentum in
actuating arms 114 is such that they may not stop immediately when
smart material device 102 reaches its expansion or contraction
limits. Ringing is exacerbated near resonance, which occurs at the
natural oscillating frequency of the physical device. Ringing, like
resonance, can create undesirable and potentially damaging
vibrations. Thus, a light weight overall structure increases the
resonant frequency, and the use of dampener assemblies 150 serves
to dampen ringing.
[0045] FIGS. 5 and 6 illustrate the dampening effect dampener
assemblies 150 have on ringing behavior. FIG. 5 illustrates the
natural ringing behavior of an actuator assembly without dampener
assemblies 150, whereas FIG. 6 illustrates the behavior of an
actuator assembly with dampener assemblies 150. Note that after
oscillation is initiated at first initiation point 304 in FIG. 5, a
naturally dampening oscillation occurs as would normally be
expected. However, when oscillation is initiated at second
initiation point 324 in FIG. 6, there is a significant reduction in
oscillation and, hence, ringing when dampener assemblies 150 are
utilized.
[0046] The dampening effect achieved with dampener assemblies 150
has a further effect. During the period of time in which actuating
arms 114 come into contact with inner pliable stop 156 and outer
pliable stop 154, the overall system is stiffer and has a higher
resonant frequency.
[0047] It will be clear to those of ordinary skill in the art that
dampener assemblies 150 are but one means of dampening oscillation
appropriate for use in embodiments of the present invention. Other
means may also be used including, without limitation, replacing
inner pliable stop 156 and outer pliable stop 154 with a flat
elastomer or a spring. More complex molded shapes could also be
used, as well as placement of stopping means in a surrounding
casing, as is illustrated in FIG. 7.
[0048] Referring to FIG. 7, actuator assembly 400 is essentially
identical to actuator assembly 100 except that it is mounted within
outer casing 402. Outer casing 402 may be of any suitable material
including without limitation aluminum, steel, plastic or
fiberglass. Inner dampening posts 256 and outer dampening posts 254
are adapted such that actuating arms 114 are prevented from moving
beyond predetermined locations. Inner dampening posts 256 and outer
dampening posts 254 may conveniently be formed as part of outer
casing 402 or may be attached to it. Surrounding inner dampening
posts 256 and outer dampening posts 254 with Buna rubber, an
elastomer, or a similar pliable material enables them to operate in
a manner substantially similar to the operation of inner pliable
stop 156 and outer pliable stop 154 of dampener assemblies 150.
Outer casing 402 may be formed in a clamshell configuration or left
open, depending on the environment in which it is needed to
operate.
[0049] Further illustrated in FIG. 7, is compensator 103'.
Compensator 103' is serves the same function as compensator 103,
but instead of being attached to first resilient member 110
mechanically, it is formed integral to mechanical webs 113 as part
of a single component.
[0050] FIG. 3 illustrates an embodiment of the actuator assembly of
the present invention adapted to operate an air valve assembly 200.
It is understood that actuator apparatuses according to the present
invention may also serve many other purposes; the illustration of
air valve assembly 200 merely being illustrative of one appropriate
application. Many other applications and attachment structures will
be apparent to those of skill in the art, all within the scope of
the present invention.
[0051] Air valve assembly 200 comprises valve casing 206, within
which valve 212 operably attached to valve stem 204 is mounted.
Pressurized air, or any other appropriately pressurized gas, vapor
or fluid, enters valve inlet 208. When valve 212 is raised by valve
stem 204, the pressurized air or other gas, vapor or liquid, is
expelled from valve outlet 210. As illustrated, valve stem 204
operably connects to second stage attachment surface 184. Such
connection can be made through use of a press-fit, threaded
fastener, weld, adhesive, or any of a variety of connecting means
known to those of skill in the art. Mounting bracket 202, which is
further illustrated in FIG. 8, attaches valve casing 206 to
compensator 103,103' preferably by way of threaded mechanical
fasteners 191. Forming mounting bracket 202 in a U-shape allows
resilient strips 182 and second stage attachment surface 184 to
move freely while air valve assembly 200 remains fixedly attached
to compensator 103, 103'. In this way, activation of actuator
apparatus 100 causes valve 212 to open and closed at appropriate
times. Where pressurized air is used, a brief burst of air may thus
be generated. The higher the speed at which actuator assembly 100
is capable of operating, the shorter the duration of air burst is
possible.
[0052] In light of the foregoing description and the incorporated
references, it will be understood by those of ordinary skill in the
art that embodiments of the present invention may include actuating
arms 114 of different lengths, or that extend away from compensator
103, 103' or that are adapted such that they are not substantially
parallel to smart material device 102 and, instead, are adapted and
mounted such that the angle between the central axis of smart
material device 102 and actuating arms 114 ranges from zero to
ninety degrees (with angles of zero degrees and between thirty and
sixty degrees being suitable for various applications) in
embodiments in which actuating arms 114 extend toward compensator
103, 103', and ranges from ninety to one hundred eighty degrees
(with angles of one hundred eighty degrees and between one hundred
twenty and one hundred fifty degrees being suitable for various
applications) in embodiments in which actuating arms 114 extend
away from compensator 103, 103'
[0053] It will be further understood that second stage assemblies
180, 180' (illustrated in FIG. 9) may also be adapted to be of
different lengths and to have different angles with respect to
actuating arms 114. This not only allows for the use of actuating
arms 114 adapted to be mounted at an angle, it also allows for
adjustment of the stroke length and force. Based on the geometry of
the desired configuration, an actuator apparatus with a second
stage assembly angled such that it extends further away from second
actuating arm ends 116 can be expected to generate greater force,
but with a shorter stroke length. Similarly, an actuator apparatus
with a second stage assembly angled such that it does not extend as
far away from second actuating arm ends 116 can be expected to have
a greater stroke length, with a somewhat reduced force.
[0054] It will be still further understood that with actuating arms
114 of suitable length, second stage assemblies 180, 180' may be
mounted to extend outward from second actuating arm ends 114 or
inward from second actuating arm ends 114. By reversing second
stage assembly 180, 180', the direction of motion upon activation
and deactivation of the actuator apparatus can be reversed.
[0055] Referring to FIG. 9, an embodiment of the actuator apparatus
of the present invention is illustrated in which actuator apparatus
500 (illustrated without smart material device 102 installed) is
adapted such that actuating arms 114 extend away from compensator
103' at an angle of one hundred eighty degrees. In such
configurations, substantially upon activation of actuator apparatus
500, second actuating arm ends 116 are urged apart. Second stage
assembly 180' is mounted to extend inward from second actuating arm
ends 114. Thus, when second actuating arm ends 116 move apart,
second stage attachment surface 184' moves outward, and when second
actuating arm ends 116 move together, second stage attachment
surface 184' moves inward.
[0056] Second stage assembly 180', as illustrated, differs from
second stage assembly 180 in that resilient strips 182' and second
stage attachment surface 184' are integral as opposed to being
mechanically attached. Such embodiments may be manufactured by
forming second stage assembly 180' from a single piece of material
(such as spring steel) and forming bends such that the desired
angles result. Such embodiments can be both lighter and easier to
manufacture than embodiments having mechanically attached second
stage attachment surfaces 184.
[0057] In light of the foregoing description, the embodiments of
the present invention can be seen to include an actuator apparatus
100 comprising a smart material device 102, a compensator 103,
103', a movable supporting member 109, two mechanical webs 113, two
actuating arms 114, and a second stage assembly 180, 180' wherein
(a) said mechanical webs 113 comprise a first resilient member 110
operably attached to said compensator 103, 103' and a second
resilient member 111 attached to said movable supporting member
109; (b) said movable supporting member 109 comprises a first
mounting surface 108; (c) said smart material device 102 is affixed
between said first mounting surface 108 and said compensator 103,
103'; (d) said actuating arms 114 comprise a first actuating arm
end 115 attached or integral to one said mechanical web 113 and an
opposed second actuating arm end 116 attached to said second stage
assembly 180, 180'; and (e) said second stage assembly 180, 180'
comprises resilient strips 182, 182' having a first resilient strip
end 181, 181' attached to said second actuating arm end 116 and a
second resilient strip end 185, 185' operably connected to a second
stage attachment surface 184, 184' wherein application of an
electrical potential causes said smart material device 102 to
expand, thereby urging said movable supporting member 109 away from
said compensator 103, 103' and causing said first and second
resilient members 110, 111 to flex, thereby moving said actuating
arms 114 and causing said resilient strips 182, 182' to urge said
second stage attachment surface 184, 184' in a direction
substantially parallel to said smart material device 102.
[0058] Embodiments of such an actuator apparatus of are also
convenient wherein said resilient strips 182, 182' are formed of a
material selected from the group consisting of steel, spring steel,
carbon fiber, fiberglass, plastic, stainless steel, and
aluminum.
[0059] Embodiments of such an actuator apparatus of are also
convenient wherein said second stage attachment surface 184 is
formed of a material selected from the group consisting of carbon
fiber, steel, spring steel, fiberglass, plastic, stainless steel,
and aluminum.
[0060] Further embodiments of such an actuator apparatus may
comprise at least one dampener 150 attached to said compensator
103, 103' and movably attached to at least one said actuating arm
114, said dampener 150 comprising a pliable stop 156 between said
actuating arm 114 and said compensator 103, 103'.
[0061] Still further embodiments of such an actuator apparatus may
comprise an outer frame 402, said outer frame 402 comprising an
inner dampening stop 256 and an outer dampening stop 254 for each
said actuating arm 114 wherein said outer dampening stop 254 is
adapted to prevent said actuating arm 114 from overextending in the
outward direction and said inner dampening stop 256 is adapted to
prevent said actuating arm 114 from overextending in the inward
direction.
[0062] Embodiments of such an actuator apparatus are also
convenient wherein said first resilient strips 182' are integral
with said second stage attachment surface 184', or wherein said
second resilient strip ends 185 are attached to said second stage
attachment surface 184.
[0063] Embodiments of such an actuator apparatus may also be used
to form an actuated valve by further comprising a valve assembly
200 attached to said compensator 103, 103', said valve assembly 200
comprising an inlet 208, an outlet 210, and a valve 212 in between
said inlet 208 and said outlet 210, and a valve stem 204 operably
connected to said valve 212 and to said second stage attachment
surface 184, 184' wherein movement of said second stage attachment
surface 184, 184' causes said valve stem 204 to operate said valve
212. In particular, such embodiments are convenient wherein said
valve assembly 200 is an air valve.
[0064] Such actuator apparatuses may further comprise two dampeners
150 attached to said compensator 103, 103' and movably attached to
each said actuating arm 114, said dampeners comprising a two
pliable stops 154, 156, one said pliable stop 156 being positioned
between said actuating arms 114 and said compensator 103, 103'.
[0065] Embodiments of such an apparatus may also be convenient
wherein said resilient strips 182, 182' extend away from said
second actuating arm ends 116 such that movement of said second
actuating arm ends 116 toward said smart material device 102 urges
said second stage attachment surface 184, 184' away from said
compensator 103, 103'. Alternative embodiments may be convenient
wherein said resilient strips 182, 182' extend toward said
compensator 103, 103' such that movement of said second actuating
arm ends 116 toward said smart material device 102 urges said
second stage attachment surface 184, 184' toward said compensator
103, 103'.
[0066] For some applications, embodiments of such an apparatus may
be convenient wherein said actuating arms 114 extend toward said
compensator 103, 103'. For other applications, embodiments may be
convenient wherein said actuating arms 114 extend away from said
compensator 103, 103'.
[0067] Embodiments of such an apparatus are also convenient wherein
(a) a central axis through the center of said smart material device
102 extends through the center of said first mounting surface 108;
(b) an actuating arm axis extends through each said actuating arm's
first actuating arm end 115 and said actuating arm's 114 second
actuating arm end 116; and (c) said central axis and each said
actuating arm axis are substantially parallel when said smart
material device 102 is not activated.
[0068] Other embodiments are convenient wherein (a) a central axis
through the center of said smart material device 102 extends
through the center of said first mounting surface 108; (b) an
actuating arm axis extends through each said actuating arm's 114
first actuating arm end 115 and second actuating arm end 116; and
(c) the angle between said central axis and each said actuating arm
axis is between zero and eighty-nine degrees, or between thirty and
sixty degrees.
[0069] Additionally, certain embodiments in which thermal
compensation and interchangeable parts are not required are
convenient wherein said compensator 103' is integral with said
mechanical webs 113. Other embodiments in which thermal
compensation and interchangeable parts are desirable are convenient
wherein said compensator 103 is mechanically attached to said
mechanical webs 113.
[0070] While the foregoing describes preferred embodiments of the
actuator assembly and air valve assembly of the present invention,
the present invention shall not be limited to those embodiments as
many other embodiments will be readily apparent to those of
ordinary skill in the art. It will also be understood by those of
ordinary skill in the art, that while the embodiments described
above and displayed in the figures demonstrate one set of
applications for the present invention, the present invention is
not limited to the specific applications described as high speed
actuators of the present invention have many applications in
various fields.
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