Flat motors

A flat motor. The flat motor comprises a substrate, a cantilevered, resilient lever arm mounted, by a passive end, on the substrate; and a shape-memory transducer acting on the lever arm wherein movement of the transducer deflects the lever arm.

FIELD OF THE INVENTION 
This invention relates generally to thermal motors, more particularly, to 
flat shape-memory-material-driven motors or devices. 
BACKGROUND OF THE INVENTION 
Much of the work in the creation thermal motors has focused on mechanisms 
which exploit actions, or movements, which occur when thermal materials 
such as bi-metals, or shape-memory alloys are successively warmed and then 
cooled. 
Some mechanisms have been aimed at replacing the functions of 
electromagnetic motors, actuators or solenoids, particularly in situations 
which require compact size or relative low-weight. In part, such devices 
have attempted to exploit the advantages of devices made using thermal 
materials which, while providing equivalent force, can often be lighter or 
smaller than conventional electromagnetic motors or solenoids with bulky 
windings and heavy magnets or cores. These devices have often employed 
bi-metals or memory-metal wires, springs, rods or strips which, when 
heated, move a rigid, pivoted lever or gear. Then upon cooling of the 
thermal material, the rigid lever, or gear, is returned to starting 
position by a biasing means-often a conventional extension spring-acting 
opposite to the thermal material's direction of force. In some of these 
devices, memory-metal actuator wires, functioning as transducers, are 
ohmically warmed using electric current as a power source and ambient air 
as the cooling means. 
A further refinement of such devices occurred with the addition of 
electronic circuits which could control the timing of electric currents 
activating the shape-memory transducers. Still further improvements 
occurred with the development of devices employing secondary levers or 
gears to amplify and transform relatively small movements of the bi-metal 
or memory-metal transducers in mechanical assemblies. 
While such devices provide some measure of usefulness, nearly all are 
application specific, i.e., in nearly all cases, new mechanisms must be 
designed "from the ground up" for each particular end use. In comparison, 
readily-available "off-the-shelf" electromagnetic motors and solenoids 
enable designers and engineers to quickly develop a multiplicity of 
mechanisms to suit an individual task or application. 
Moreover, many devices employing thermal materials have been relatively 
difficult and expensive to manufacture. For example, devices employing 
pivoted levers, gears or other rigid elements connected to memory-metal 
actuator wires often must be made with exacting part tolerances since 
small mismatches (e.g. "backlash" between gears, or pivots and pivoting 
members) would otherwise waste much of the shape-memory materials' short 
"stroke," which is typically only 3 to 7 percent of active length. 
Additionally, many devices provide essentially fixed torque though out 
their "power-strokes" when it is desirable to have a responsive capability 
since it is often necessary to overcome relatively greater force at only 
start of a cycle or to respond to temporary increase demand for a greater 
torque for a small part of operating cycle. Consequently, many of the 
devices have been inefficient in the use of relatively expensive 
shape-memory-material. 
Also, some devices employ separate, costly strain-reliefs to avoid 
over-stressing or breaking shape-memory elements if mechanism travel 
becomes blocked or restrained during operation. Other devices make no 
provision for strain relief at all. 
In addition, many battery-powered devices have had limited operating lives. 
These mechanisms are most often made of rigid moving parts with relatively 
high mass acted upon by thin, fast-acting memory-metal wires. 
Consequently, these mechanisms exhibit substantial inertial resistance or 
fail to absorb the shock of a "power stroke" leading to stress fatigue and 
breakage of thin actuator wires after relatively few operating cycles. 
Therefore, it is desirable to provide improved actuators and motor-like 
devices which are simple and relatively inexpensive to manufacture and yet 
can function for extended periods of time in a multiplicity of 
applications. More specifically, it is desirable to provide simple motors 
and devices employing cantilevered, resilient, shock-absorbing means in a 
efficient "pivotless" transducer. It is desirable that such devices be 
also lightweight and flat while at the same time be resistant to damage 
when operated, even when mechanism travel is blocked or hindered. 
Additionally, such devices should be efficient in the use of shape-memory 
materials and be capable of appropriately varying torque in response to 
load requirements during device operation. 
SUMMARY OF THE INVENTION 
The present invention describes a flat motor. The flat motor comprises a 
substrate, a cantilevered, resilient lever arm mounted, by a passive end, 
on the substrate; and a shape-memory transducer acting on the lever arm 
wherein movement of the transducer deflects the lever arm. 
In one embodiment of the present invention the active end of the lever arm 
engages a latch to thereby release the latch when the transducer is 
activated. In another embodiment of the present invention a electrically 
conductive strip and a plurality of electrically conductive elements 
attached to the substrate adjacent to the strip are bridged by a wiper arm 
to complete an electrical circuit with the memory transducer to thereby 
move the crank to a preselected position. In another embodiment of the 
present invention finger arms attached to a bracket, which in turn is 
attached to the lever arm, engage a sprocket wheel.

DETAILED DESCRIPTION 
The present invention relates to flat motor devices. The flat mechanism 
employs a cantilevered, resilient lever arm, directly driven by a 
shape-memory transducer. 
Shape-memory materials have the property of returning to a pre-set shape 
from a deformed, often stretched, state on heating and/or with electrical 
stimulation (the property of "memory"). The force at which the 
shape-memory-material, on heating, tends to return to pre-set shape is 
often several times the force required to deform it when "cold." Practical 
shape-memory materials are generally comprised of metal alloys, but 
certain plastics or other non-metallic materials also exhibit shape-memory 
properties and thus may be employed in making force transducers. 
For a shape-memory-metal alloy, the transformation temperature--the 
temperature at which the alloy transitions to its "memory" shape through 
changes to its internal crystal structure--can be chosen to be anywhere 
from well above +100.degree. C. to below -100.degree. C. by controlling 
the alloy content (many are primarily NiTi alloys) during fabrication. 
Persons skilled in the art will readily recognize that it is necessary to 
pick the correct material transition temperature in order to ensure the 
flat motor's action occurs only when desired. As well, nearly all 
shape-memory-materials exhibit hysteresis with respect to temperature and 
change of internal structure--this means the materials must cool somewhat, 
about 30.degree. C. for most NiTi alloys, below their transition 
temperature before they can again be easily deformed, or stretched, 
without damage. Further, in order for the assembly to function, as persons 
skilled in the art will readily understand, the generated force of the 
shape-memory material must be greater than the total of the friction and 
other forces resisting the action of the shape-memory material. 
Referring now to FIG. 1, a flat motor of the present invention is generally 
designated as 100. More particularly, as a first embodiment of the present 
invention, a flat, reciprocating motor mechanism, 100, is shown. Motor 100 
is fabricated with a cantilevered, resilient lever arm 101 mounted to 
rigid support structure, 111, preferably a circuit board, by mechanical 
means or by solder or preferably glue, 109. A preferred mounting glue is 
cyanoacrylate, available from Radio Shack. A length of memory-metal 
actuator wire, 107, is looped around a sleeve, 105, which covers a portion 
of lever arm 101. Crimps, 113, fasten the ends of actuator wire 107 to 
support structure, or to circuit board, 111. The looped memory-metal wire 
is tensioned so as to stretch "cold" actuator wire approximately 4 to 5 
percent in length as compared to its length under normal load for the 
wire's diameter. Detailed information about tension and normal load 
specifications is published and can be obtained from memory-metal wire 
manufacturers, such as Dynalloy of Newport Beach, Calif. 
A portion at the far end of the cantilevered lever arm 101, the designated 
area 115, loops around crank 117 which is mounted though pivot 121 located 
on structure 111. Alternative pivot mounting holes, 122, are formed in 
support structure 111 so that the crank's pivot location can be changed 
and in turn the extent of crank rotation as well as the amount of torque 
provided can be adjusted easily. When actuated by a timed pulse of 
electric current from circuit shown in area 123, memory-metal actuator 
wire 107 contracts, pulling lever arm 101 to a new position, shown by 
dotted outline 103. In turn, the looped portion of wire shown in area 115, 
in contact with crank 117, moves it to a new position shown in dotted 
outline 119. 
Timing circuit shown in area 123 can be constructed from one of a 
multiplicity of oscillator circuits well known in the art. In addition, 
support structure 111, preferably a printed circuit board, is constructed 
by conventional means also well known in the art. 
At the cessation of the electric-power pulse supplied by electric circuit 
shown in area 123, memory-metal actuator wire 107 is cooled preferably by 
ambient conditions and resilient lever arm 101 acts to deform, or stretch, 
actuator wire 107. While ambient air cooling is preferred, other 
alternative cooling means are well known in the art if expected ambient 
conditions are determined to provide insufficient cooling for desired flat 
motor operation. Upon actuator wire cooling, lever arm 101 and crank 117 
all return back to starting position, ready to begin another cycle. Thus, 
when electrical leads 125, are connected to a power supply, flat motor 100 
will reciprocate back and forth indefinitely. 
Memory-metal actuator wire 107 is readily available "off the shelf" (such 
wires are available from Dynalloy, Inc. of Newport Beach, Calif.). All 
other things being equal, the larger the diameter of wire which is used, 
the greater the force generated when the wire is heated, and consequently 
the more readily the memory-shaped wire overcomes the mechanical and 
friction forces resisting its action. The faster the wire is heated to 
transition temperature the sooner the wire will move. Put another way, 
increasing current flow increases the speed of actuation. However, even 
with unlimited power availability the relative slow speed of cooling can 
limit the usefulness of large diameter wires since they may return to 
position more slowly than the application requires, since, everything else 
is equal, large diameter wires cool more slowly than small diameter wires. 
As well, large wire diameters generally have low electrical resistance and 
require substantial electrical current for actuation. In addition, all 
other things being equal, the length of the wire loop used can be changed 
to affect its travel and force properties. Increasing shape-memory 
lengths, however, increases the assembly's space requirement, and the 
overall size of the assembly can become impractical. Thus, even without 
limits on power availability, multiple strands of relatively thin 
memory-metal wire acting in parallel are often better than a single long 
strand of large diameter wire. For the foregoing reasons, persons skilled 
in the art will readily understand that the shape-memory wire, or wires, 
must be chosen which have suitable dimensions in order to match: 1) the 
assembly's force and operating requirements, 2) the limitations of the 
power supply, and 3) the speed of the movements required. 
For most portable, battery-powered applications-such as in toys or 
hand-held devices-actuator wires sized from about 0.001" diameter to about 
0.006" diameter are preferred. These preferred wire sizes heat quickly 
(from ohmic heating) to the required transition temperature with the 
current flow induced from connection to battery-power supplies. Preferably 
a 4.5 volt (V) or greater power supply is used since this voltage provides 
sufficient current to heat the shape-memory wire quickly, especially wire 
sizes less than 0.002" in diameter. Preferably voltages greater than 3 V 
should be used for wire sizes 0.002" diameter and above, but in some 
instances 1.5 V power supplies can be used. In situations where larger 
diameter memory-metal wires (diameters above about 0.006") or strips-or 
assemblies with more than a few strands of small diameter wire-greater 
current flow than portable batteries-of hand-held size, at least-typically 
supply, are required. In these situations conventional household or 
industrial power (typically employing a voltage-step-down transformer) or 
automotive generator power can be used so long as the voltage (or current) 
supplied is properly matched to the wire size. Memory-metal wire 
manufacturers, such as Dynalloy of Newport Beach, Calif., can provide 
detailed specifications for matching voltage (or current) requirements, 
speed of action, cooling techniques and wire size. 
The extent, or amount, of lever movement, or rotation, around the bend 
point, or locus of flexure, can be controlled by the point of application, 
106, of the memory-metal wire along lever arm 101 as well as by the total 
length of the shape-memory-material loop used. Loop formed by the actuator 
wire 107 and cantilevered lever arm 101 form, in effect, a third-class 
lever. Thus, knowing the pivot point, or locus of flexure shown in area 
108, point of application 106 and the length of cantilevered lever arm 
101, the "moment arm" can be calculated. As well, greater forces can be 
obtained by making multiple loops of shape-memory-material wire, so that 
assemblies capable of overcoming large resistive forces can constructed 
according to the principles of the present invention. Assemblies 
constructed in the spirit and scope of the present invention can be made 
with shape-memory springs, rods or thin strips, or wires with non-circular 
cross sections in place of round memory-metal wires. 
While lever-arm 101 can be made from one of a plurality of other resilient 
materials well known in the art, it is preferably constructed of 
high-grade music wire. However, whichever material is chosen, lever-arm 
spring material is preferably resistant to fatigue from repeated flexures. 
The diameter of the music wire preferred in making lever arm 101 is larger 
in diameter, preferably 5 to 8 times the diameter of the memory-metal 
actuator wire. Lever-arm 101 also is preferably configured to achieve 
about 3 to 6 times stroke amplification. In other words, end shown in area 
115 preferably moves 3 to 6 times the distance that memory-metal loop 
formed in actuator wire 107 contracts. Lever-arm 101 is preferably arched, 
or curved, in shape as well. Among other things, lever arm's preferred 
arch shape permits it to clear pivot 121 during reciprocal motion. The 
preferred "M" form, indicated in area 108, fabricated in a portion of 
cantilevered lever arm 101 help define locus of the bend, or flexure, of 
lever arm 101. 
Cantilevered lever arms with forms alternative to the preferred "M" form 
can be constructed according to the principles of the present invention 
and still achieve its objectives. For example, the area 108, the locus of 
the bend or flexure, of lever arm 101 can be made as a loop, or coil, and 
still achieve the principles of the present invention. 
Sleeve 105 is preferably made from rugged, high-temperature plastic. Teflon 
shrink tube, which can be obtained from Radio Shack, is preferred. Sleeve 
105 preferably acts to cushion the wire at point of application, located 
approximately as indicated by point of application 106. As well, sleeve 
105 increases the effective diameter of the bend radius of the 
memory-metal loop. Sharp bends, i.e. loop diameters less than about 20 
times the diameter of memory-metal wires, can lead quickly to their stress 
fracture or breakage during flat motor operation. Sleeve 105 consequently 
should be thick enough to create an adequate bend radius for the loop of 
memory-metal. Sleeve 105, although presently preferred for ease of 
assembly, can be eliminated since the memory-metal wire can be directly 
attached to lever arm 101, using lever arm 101 as a conductor to complete 
the electrical circuit and the assembly will function within the spirit 
and scope of the present invention 
When constructed according to the principles of the present invention, 
lever arm 101 will tend to beneficially absorb the shock of the 
memory-metal actuator wire 107 contractions during flat motor operation. 
As well, persons skilled in the art will understand readily that lever arm 
101, made according to the principles of the present invention, will 
yield, or flex, if the motion of crank 117 is blocked, easing what 
otherwise would be substantial stress on the wire of loop formed by 
actuator wire 107--stress substantial enough to quickly lead to fatigue or 
breakage of loop formed by actuator wire 107. If motion of crank 117 is 
hindered, or restrained, the arch of resilient lever arm 101 will tend to 
flatten causing point of contact shown in area 115 between lever arm 101 
and crank 117 to slide out away from pivot 121, substantially increasing 
the effective length of the "moment arm" formed by point of contact shown 
in area 115 and pivot 121, while only moderately increasing the moment of 
lever arm 101 with respect to point of application 106--thus temporarily 
increasing the torque provided. Once the hindrance, or restraint, is 
overcome, lever arm 101 will tend to "spring" back to a fully-arched shape 
and point of contact shown in area 115 will tend to return to a "normal" 
position in power-stroke cycle. Accordingly, flat motor 100, when 
constructed according to principles of the present invention, will act to 
respond to different torque requirements during operation. 
Referring now to FIG. 2, a second embodiment of the present invention, 
generally designated as flat motor 200 is shown. Cantilevered, resilient 
lever arm 201, is constructed in the manner described earlier with regard 
to lever arm 101 in FIG. 1 and is mounted in, or on, a structure 203. 
Support structure 203 is preferably fabricated from structural plastic 
such as 6/6 Nylon (a trademark of DuPont Co., Wilmington, Del.), from 
folded sections of rigid paper card-stock, or from conventional 
circuit-board material. It is preferred that support structure 203 be made 
fire retardant, which can be accomplished by conventional means well known 
in the art, such as using fire-retardant additives in support-structure 
fabrication. Mounting holes 205 and 217 are preferably fabricated in 
support structure 203 so that flat motor 200 can be affixed to a main 
support means in use. Memory-metal loop 213 is constructed according to 
the principles of the present invention described earlier with regard to 
flat motor 100. Similarly as with embodiment of flat motor 100, a loop of 
memory-metal wire, 213, is attached to lead wires 207 by means of crimps 
211 and glued or attached to support structure 203 as designated by 209. A 
preferred mounting glue is cyanoacrylate, available from Radio Shack. Slot 
210 is formed in the support structure 203 to further hold crimps and a 
right-angle portion of lever arm 201 in place. Active end designated by 
221 can be formed in a loop shape as in embodiment of flat motor 100 above 
or in any of a number-of shapes some of which will be described below and 
a plurality of other shapes, or constructions, as are well known in the 
art. Support structure 203 is also preferably constructed with stops 215 
and 219 which limit travel of lever arm 201 and prevent over-stretching or 
disengagement of actuator wire loop 213. A plurality of flat or thin 
solenoid-like devices can be constructed in accordance with the principles 
of the present invention. Moreover, since non-magnetic memory-metal 
materials are readily available (e.g. NiTi memory-metal materials are 
generally non-magnetic), by employing non-magnetic materials for all the 
moving parts of flat motor 200, including lever arm 201, solenoid-like 
embodiments of the present invention can be fabricated which will function 
nominally even in the presence of strong magnetic fields. Furthermore, 
tiny actuator devices can be constructed, according to the principles of 
the present invention, using very small diameter wires for both the 
memory-metal loop and lever arm. Thus, a plurality of flat solenoid-like 
devices can be constructed, within the spirit and scope of the present 
invention, by simply modifying memory-metal and lever-arm wire sizes, 
choosing a suitable mounting structure, and determining--among a 
multiplicity well known in the art--the desired shape for active end 221. 
Accordingly, actuator devices constructed according to the principles of 
the present invention can easily be fabricated small enough to fit in the 
body of wrist watch, for example. Other embodiments of the present 
invention could be made large and strong enough to power automotive 
windshield wipers, for example. Still other preferred embodiments of the 
present invention are described more fully below. 
Referring now to FIG. 3, a third embodiment of the present invention, a 
latch-release mechanism, generally designated as flat motor 300 is shown. 
Support structure 307 is made in the same manner as is structure 111 in 
FIG. 1. Cantilevered lever arm 319, except for modifications as described 
more fully below, is constructed in the manner described earlier with 
regard to resilient lever arm 101 in FIG. 1 and is mounted on support 
structure 307 by mechanical means, 313 and 317, as is well known in the 
art. Memory-metal wire 315 is looped around lever arm 319 and held in 
place under tension by crimps 309 which, in turn, are mounted on support 
structure 307 and connect to wire leads 311. Latch 301, which is mounted 
to support structure 307 by pivot 329, engages shaft 327. Shaft 327 moves 
in a direction which is approximately parallel to the base of support 
structure 307. A multiplicity of locations for use of flat motor 300 such 
as when shaft 327 is mounted on, or part of, a gate or door means, e.g. on 
a vending machine. Lever arm 319 is fabricated to form a curved section 
323 which engages against pin 325 on latch 301, holding latch arm closed 
until released by action of lever arm 319. Spring 305 is mounted between 
support structure 307 and latch 301 and is in tension when the latch arm 
is closed around shaft 327. Block 321 acts to support and prevent 
over-travel of lever arm 319. 
Latch-release begins when memory-metal wire 315 is energized with a pulse 
of electric current or when it is otherwise warmed to its transition 
temperature. Lever arm 319 moves in response and curved section 323 moves 
to release pin 325. Spring 305 acting on latch 301 moves it to position 
shown in dotted outline 303. Shaft 327 is then released. The latch 
mechanism flat motor 300 is "re-set" when shaft 327 is re-engaged with 
latch 301, causing pin 325 to ride up and over the curved section 323 of 
lever arm 319 which, in turn, "springs" back to hold pin 325 in the 
"latched" position. 
A plurality of thin or flat latch release mechanisms can be made 
constructed according to the principles of the present invention. 
Furthermore, mechanisms can also be fabricated to very small and operate 
in unusual environments such as ones with high magnetic fields. Moreover, 
latch-release mechanisms of flat motor 300, fabricated according to the 
principles of the present invention, can be employed to release at 
pre-selected elevated temperatures, e.g. as latch-releases for a fire door 
in a building or structure. 
Referring now to FIG. 4, a fourth embodiment of the present invention, a 
multi-position "stepper" mechanism, generally designated as flat motor 400 
is shown. Support structure 421 is made in the same manner as is structure 
111 in FIG. 1, preferably as a conventional circuit board. As well, arm 
401 is constructed in the manner described earlier with regard to 
resilient lever arm 101 in FIG. 1 and is mounted on a structure 421. Arm 
401 is mounted by mechanical means or preferably by glue, 417, to 
structure 421. A preferred mounting glue is cyanoacrylate, available from 
Radio Shack. In the manner described earlier with regard in FIG. 1, crimps 
415 and memory-metal loop 419 are mounted. Pivot 403 and crank 405 are 
also constructed in the manner described earlier with regard to pivot 121 
and crank 117, respectively, in FIG. 1. Wiper arm 409, which is connected 
to rotate in concert with crank 405, makes simultaneous contact with 
sector 407 and successively with arc segments 411a through 411d, depending 
on the extent of rotation, or position, of crank 405. Crank 405 is shown 
in starting position 405a and in dotted outline form in positions 405b 
through 405c. Sector 407 and arc segments 411 are preferably exposed 
conductors, of a conventional circuit board. Connector 413 is also shown 
mounted on board 421 and electrically connected to crimp 415a, though 
memory-metal loop 419, 415b and sector 407, and then selectively to each 
individual arc segment 411a through 411c by means of conductive wiper arm 
409. Each arc segment, 411a through 411c, is separated from the other by a 
narrow, non-conductive gap. Wiper arm is 409 is fabricated to be less than 
the width of an individual arc segment but wide enough to "bridge" each 
one of the narrow, non-conductive gaps between the arc segments of 411. 
Flat motor 400 is operated by closing the electrical circuit from 415a and 
then successively to each element 411a through 411d. The position of crank 
405 will quickly "step" when the circuit is engaged in this manner. When 
arc segment 411a and 441b is powered, crank 405 will move to position 
405b, to 405c if 411a through 411c are energized, and so forth. In each 
instance, wiper arm 409 will tend to move so that it is barely in contact 
with the last energized arc segment. The number of arc segments can be 
increased for even finer control of crank position. Concentric rings of 
conductors of differing arc lengths will function in place of individual 
arc segments. Furthermore, electric switching can occur manually by 
connecting conventional switches to connector 413 or by electronic 
switching circuitry fabricated on the circuit board. Additionally, a 
plurality of thin, light-weight, multi-position devices can be constructed 
according to the principles of the present invention. For example, 
multi-position mechanisms, constructed within the spirit and scope of the 
present invention, could be integrated with radio-control circuitry, in 
the creation of inexpensive, lightweight control systems for models and 
toys. As well, other multi-position mechanisms, also constructed within 
the spirit and scope of the present invention, could be employed pointing 
or indicating systems in instruments or gauges. 
Reference is now made to FIG. 5, a fifth embodiment of the present 
invention, a continuously-rotating sprocket-wheel mechanism, generally 
designated as flat motor 500. Support structure 531 is made as is 
structure 111 in FIG. 1, preferably as a conventional "printed" circuit 
board. As well, arm 501 is constructed in the manner described earlier 
with regard to lever arm 101 in FIG. 1 and is similarly mounted on a 
support structure 531. While any of a multiplicity of materials are 
possible and well known in the art, sprocket wheel 503 is preferably 
fabricated from structural plastic such as 6/6 Nylon, made by DuPont 
Corporation. Pivot 505 and crank 511 are also constructed in the manner 
described earlier with regard to pivot 121 and crank 117, respectively, in 
FIG. 1. 
Arm 501 is mounted by mechanical means, by solder or preferably by 
cyanoacrylate glue to support structure 531. In the manner described 
earlier with regard in FIG. 1, crimps and memory-metal loop 507 are 
mounted as well. Finger arms 515 and 527, which rotate about pivots 521 
and 529 respectively, are held in place against sprocket wheel 503 by 
springs 517 and 530, respectively. Finger arms, 515 and 527, via pivots 
521 and 529 are mounted on bracket 519. Bracket 519, connected to crank 
511, turns about pivot 523, which, in turn, is mounted to support 
structure 531. 
Electrical circuit shown in dotted area 509 is constructed in the manner 
described with regard to timing circuit shown in area 123 in FIG. 1. Also 
in the same manner as flat motor 100 in FIG. 1, electrical leads 525 are 
connected to a power source. 
Flat motor 500 will function indefinitely, in the manner of flat motor 100, 
so long as electric power is supplied to the circuit which provides timed 
pulses of electric power to periodically ohmically heat memory-metal wire 
loop 507. Memory-metal loop 507 by alternately contacting and relaxing 
causes cantilevered, resilient lever arm to move back and forth between 
the position shown for solid arm 501 and position shown by dotted outline 
502. Thus finger arms 515 and 527 alternately power sprocket wheel 503, 
one after the other in turn. On the "down" stroke, i.e. crank moving from 
position 511 to the position shown for dotted crank 513, finger arm 515, 
engages and turns sprocket wheel 503 clockwise. While this occurs, finger 
arm 527 slides up and over a sprocket of wheel 503. On the "up" stroke, 
i.e. the crank is moving back from the position shown for dotted crank 513 
to the position shown for solid crank 511, finger arm 527 engages and 
turns a sprocket of wheel 503 while finger arm 515 returns to the position 
shown for solid crank by sliding up and over another sprocket. 
A plurality of thin, light-weight, sprocket-wheel, or ratchet, devices can 
be constructed according to the principles of the present invention. 
Referring now to FIG. 6, a sixth embodiment of the present invention, a 
relay mechanism, generally designated as flat motor 600 is shown. Support 
structure, preferably constructed as conventional circuit board, 607 is 
made as in structure 111 in FIG. 1. Cantilevered lever arm 601, except for 
modifications as described more fully below, is constructed in the manner 
described earlier with regard to resilient lever arm 101 in FIG. 1, and is 
mounted on support structure 607 by means of glue or preferably by 
"double-stick" tape available from Radio Shack. Memory-metal wire 605 is 
looped around lever arm 601 and held in place under tension by crimps 
which are mounted on support structure 607 and connect to wire leads 623. 
Conductive arm 609, on which electrical contact 611 is affixed, is in turn 
mounted by means of pivot 619 to support structure 607. Conductive bracket 
615, on which electrical contact 617 is mounted, is also affixed to 
support structure 607. Both pivot 619 and conductive bracket 615 is 
preferably mounted by means of conventional soldering to support structure 
607. Electrical contacts 611 and 617 are preferably plated, by any 
conventional means, to prevent oxidation during use. Conductive arm 609 is 
preferably mounted under tension with cantilevered lever arm 601. As is 
well known in the art, tensioning is preferably aligned toward pivot 619 
so as to create an "over-center" or "snap" action when lever arm 601 is 
moved to position shown by dotted lever arm 603. 
When electric power is supplied via circuit positions 623, memory-metal 
loop is ohmically warmed and cantilevered lever arm 601 moves to position 
shown in dotted outline 603. This action, in turn, causes contacts 611 and 
617 to "close" by movement of conductive arm 609, which is connected to 
lever arm 601 and shown by dotted lever arm 603. Conductive arm 609 and 
bracket 617 can be fabricated and mounted in a plurality of conventional 
ways all within the spirit and scope of the present invention. 
Electrical contacts 611 and 617 are shown in the "normally-open" position, 
creating a "open," circuit by connecting to positions 621. While a 
"normally-open" configuration is illustrated, flat motor 600 can be 
configured to be "normally-closed." Additional brackets can be mounted on 
support structure 607 in order to create form "C" relay-circuit pattern, 
as well as a multiplicity of other relay-circuit patterns, all within the 
spirit and scope of the present invention. Accordingly, a plurality of 
flat relay devices can be constructed in accordance with the principles of 
the present invention. Moreover, since many common shape-memory materials 
are non-magnetic, as described more fully above with regard to flat motor 
200, flat relay devices, all within the spirit and scope of the present 
invention, can be fabricated which will function in the presence of strong 
magnetic fields. 
Referring now to FIGS. 7a and 7b, a preferred embodiment, flat motor 100, 
is shown employed in animation of a flat display panel or picture. Shown 
in FIG. 7a, flat motor 100 is mounted on back of display panel, or 
picture, 711, by glue or preferably by conventional "double-stick" tape 
available from most hardware or artist-supply outlets. Display panel or 
picture 711 is preferably backed by card board or foam board. Battery pack 
705 is connected to leads 125 and mounted, in the same manner as flat 
motor 100, to the back of panel 711 as well. 
Referring now to FIG. 7b, the front of display panel 711 is shown. Powered 
by reciprocating action of flat motor 100, hand 707 moves to position 709, 
shown as a dotted outline. Hand 707 is fabricated of lightweight card 
stock, printed on front, and affixed to crank 117. The motion of crank 117 
to position shown in dotted outline 119 is shown in FIG. 7a. The motion of 
crank 117 corresponds to motion of the hand 707 as best seen in FIG. 7b. 
Within the spirit and scope of the present invention, a plurality of 
figures or picture elements can be animated in the manner illustrated by 
FIGS. 7a and 7b. 
Reference is now made to FIG. 8a, a preferred embodiment, flat motor 200, 
shown employed in animation of a flat, trading-card-like amusement device. 
FIG. 8a shows the reverse side of device 800 without back 817. Shown in 
FIG. 8a, flat motor 200 is mounted on back of printed card-stock, or 
picture mounted on thin cardboard, 801, glued at points 803. A preferred 
mounting glue is cyanoacrylate, available from Radio Shack. 
Flat motor 200 is connected to printed circuit board 807 by leads 805. 
Circuit board 807 contains a timing circuit which, except for 
modifications noted below, is made in the manner described above with 
reference to timing circuit shown in area 123 in FIG. 1. Activation button 
809, a conventional tact switch available from most electronic supply 
outlets, e.g. Radio Shack, is added to the timing circuit and used as an 
on/off power switch. Also on circuit board 807 are battery "button" cells 
811, small 1.5 V alkaline cells, which are mounted by conventional means. 
Battery "button" cells 811 are also available from most electronic supply 
outlets, e.g. Radio Shack. 
Shown for illustrative example in dotted outline form in FIG. 8a, is 
picture 802, a figure printed on card stock. Mouth tab 813 is mounted to 
lever arm 201. Mouth tab 813 is inserted into slot 815 so as to extend 
through from the reverse to the front of printed card 801. Different 
appearances of card 801 during movement of mouth tab 813 are illustrated 
in FIGS. 8b and 8c, respectively. Clear plastic cover 819 is mounted 
preferably by conventional glue on top of card 801. Cover 819 can be made 
of acrylic or other clear plastic and is constructed so as to permit free 
movement of mouth tab 813 and activation of button 809. Back 817 is 
fabricated of any rigid plastic such as ABS plastic, which is commonly 
available from a multiplicity of plastic-supply outlets. Back 817 can be 
glued in place, using cyanoacrylate glue, on the back of printed card 801. 
As well, back 817 and clear plastic cover 819 can be made of 
injected-molded parts, fitting together as a snap-together box. Amusement 
device 800 is activated by depressing button 809, causing the figure 
printed on card 801 to appear to become animated. 
Within the spirit and scope of the present invention, a plurality of 
figures or picture elements can be animated in the manner illustrated by 
FIGS. 8a, 8b and 8c. While motion of mouth tab printed on cardstock is 
illustrated in FIGS. 8a, 8b and 8c, "bas-relief" plastic parts, "cut-out" 
cardboard parts of photographic "baseball cards" as well as a plurality of 
similar elements can be animated all within the spirit and scope of the 
present invention. As well, greeting cards, flat wrist watches, toys, 
books and book covers and plurality of flat printed or photographic 
display or advertising media can be animated in a like manner according to 
the principles of the present invention. Moreover, animated combinations 
of moving elements and "sound-sync'd" mouth movements, within the spirit 
and scope of the present invention, are easily achieved by employing 
conventional microprocessor circuits or similar control elements as are 
well known in the art. Such control elements are readily available from 
electronic-supply outlets such as Radio Shack. 
Reference is now made to FIG. 9, in which a preferred embodiment, flat 
motor 200, is shown employed in animation of a doll's eye. FIG. 9 shows a 
cross-section view of a doll's, or toy figure's, hollow head 901 and a 
pivoted eye 903, rotating on pivot 905. Both hollow head 901 and eye 903 
can be constructed by conventional means well known in the art or adapted 
from available parts. Hollow head 901 is preferably made of roto-cast 
vinyl, as is well known in the art. The doll's eye is made of painted, 
injection-molded polypropylene or preferably adapted from eyes made by 
manufacturers such as Tak Mei Eyeball Factory, Yau Tong Bay, Kowloon, Hong 
Kong. Flat motor 200 is mounted on protrusion 909, fabricated as part of 
head 901. Flat motor 200 is preferably glued at points indicated by 907 so 
as to affix it in place. Suitable vinyl glue is available from most 
hardware or artist-supply outlets. The "active end" 221 of flat motor 200 
engages pin 911 mounted on the side of the plastic eyeball 903, which in 
turn rotates about pivot 905. As persons skilled in the art will readily 
understand, actuator wire must move rapidly in order to produce 
aesthetically-pleasing eye motion--thus, preferably, 90.degree. C. NiTi 
actuator wire less than 0.002" in diameter, available from Dynalloy of 
Newport Beach, Calif. is used in fabricating flat motor 200 so as to 
achieve realistic motion. A multiplicity of conventional microprocessor 
circuits or other similar means connected to lead wires 207, in the manner 
disclosed above with reference to FIG. 8, can be used to control animation 
of the doll's eye by controlling timing of electric currents to flat motor 
200 in a large number of possible patterns and/or in response to a 
plurality of stimuli. As well, a multiplicity of pivoted, or otherwise 
moving, parts of toy figures of all kinds can be animated according to the 
principles of the present invention. For example, mouths of toy ponies can 
be animated in the according to the principals of the present invention. 
Referring now to FIG. 10, a preferred embodiment, flat motor 200, is shown 
employed in animation of a flat display panel or picture. Flat motor 200 
is mounted on back of display panel, or picture, 1001, by glue or 
preferably by conventional "double-stick" tape available from most 
hardware or artist-supply outlets. Display panel or picture 1001 is backed 
by card board or preferably foam board. Battery pack 1011 is connected to 
leads 1003 and mounted, in the same manner as flat motor 200, to back of 
panel 1001 as well. 
In the same manner as in FIG. 7a, crank 1005 is mounted through pivot 1006 
extending through panel 1001. Lever arm 201 is slipped over crank 1005. 
Permanent magnet 1009 is mounted on the free end of crank 1005 preferably 
by epoxy glue or other suitable means well known in the art. A common 
"normally-open" reed switch, 1007, available from most electronic-supply 
outlets, is spliced in series with one of leads 1003. During device set up 
and before electric power is engaged, magnet 1009 is positioned, by 
bending crank 1005, if need be, into a position near but not touching reed 
switch so that magnet 1009 activates reed switch 1007 when the apparatus 
is in rest position. Minor adjustments necessary in the spatial position 
of magnet 1009 with respect to reed switch 1007 so as to achieve the 
switching necessary for back and forth "swings" of crank 1005. As well, a 
multiplicity of reed-switch, pivot and permanent-magnet arrangements can 
employed, all within the spirit and scope of the present invention, in 
order to modify patterns of movements or to achieve additional movements 
on the front side of picture or display panel 1001. 
Referring now to FIG. 11a, a preferred embodiment of the present invention, 
a covered rotary actuator, generally designated as flat motor 1100, is 
shown with the top portion of housing 1101 cut away so that the internal 
mechanism is visible in plan view. FIG. 11b and 11c show back and side 
views, respectively, of the exterior of rotary actuator mechanism of flat 
motor 1100. Referring to FIG. 11a, cantilevered lever arm 1135, is 
constructed in the manner described earlier with regard to cantilevered, 
resilient lever arm 101 in FIG. 1 and is mounted on housing 1101. While 
assembly from injection-molded plastic parts is feasible, housing 1101 is 
preferably fabricated from stainless-steel or zinc-plated metal stampings. 
Such stampings can be made by conventional means well known the art. 
Mounting tubes 1107 are preferably fabricated from brass and affixed by 
conventional means to housing 1101. Sleeve 1103 is mounted on arm 1135 in 
the manner of sleeve 105 in FIG. 1. Memory-metal loop 1105 is constructed 
according to the principles of the present invention described earlier 
with regard to flat motor 100, in FIG. 1. Also in the manner described 
with regard to embodiment 100 in FIG. 1, a loop of memory-metal wire, 
1105, is attached to solder lugs 1113 by means of crimps 1109 and leads 
1112. Both crimps 1109 and leads 1112 are affixed to structure 1111 by 
conventional means also well known in the art. Structure 1111 is 
preferably a small circuit board fabricated by conventional means also 
well known in the art. Structure 1111 is fabricated with preferably at 
least three spring-mounting holes 1115. Biasing spring 1117 is connected, 
under tension, to crank 1127 and to one of the spring-mounting holes. 
Biasing spring 1117 is a small, common extension spring, available in 
hardware-supply outlets or from manufacturers such as Century Spring of 
Los Angeles, Calif. Biasing spring should be selected for proper size as 
well as for resistance to fatigue. Furthermore, biasing spring 1119 is not 
necessarily required for device operation, but that is useful as a 
"helper" to partially offset loads or balance objects attached to and 
moved by crank 1127. Spring-mounting holes 1115 enable adjustment of 
biasing-spring tension. While balance weights can be employed, the use of 
a spring is a preferred biasing means since it creates less inertia than a 
counter weight for the same balancing effect. Accordingly when constructed 
according to the principles of the present invention, the addition of a 
biasing means, such as a small conventional extension spring, will permit 
the substitution of thinner, more efficient actuator wires, in place of 
larger-diameter actuator wires, thereby reducing power consumption and/or 
increasing the speed of action over that otherwise possible. 
Housing 1101 is preferably constructed with stops 1129 and 1121 which limit 
travel of lever arm 1135 to a maximum extent indicated by crank 1127 in 
dotted outline form 1123, as lever arm 1135 moves to position 1133. 
Limiting travel prevents over-stretching or disengagement of memory-metal 
loop 1105. Slot 1125 is fabricated on the base of housing 1101 in the same 
manner as pivot mounting holes, 122, described in FIG. 1. When such a slot 
is employed according to the present invention, the crank's pivot location 
can be changed and, in turn, the extent of crank rotation as well as the 
amount of torque provided can be adjusted easily. Hole 1131 is one of 
several holes fabricated in the substrate for mounting it to a surface. 
Pivot 1119, as can be best seen in FIG. 11c, is fabricated of a nut 1137 
and bolt 1139. Both nut 1137 and bolt 1139 are preferably made of 6/6 
Nylon, a trademark of DuPont Corporation. The nut portion of pivot 1119 
can be loosened so as to permit adjustment of position of bolt 1139 along 
slot 1125. Bolt 1139 has an axial hole which permits passage of the end of 
crank 1127 through its length. 
Rotary actuator flat motor 1100 is actuated in the manner described with 
regard to flat motor 100, in FIG. 1. A plurality of flat rotary actuator 
flat motors can be constructed in accordance within the spirit and scope 
of the present invention, by simply modifying memory-metal and lever-arm 
wire sizes. As well, according to the principles of the present invention, 
the size of the external housing can be modified within a wide range from 
smaller in diameter than a U.S. "dime" to larger than a U.S. "silver 
dollar." 
The foregoing description should not be read as pertaining only to the 
precise structure, as described and shown in the accompanying drawings, 
but rather should be read consistent with and as support to the following 
claims which have their fullest and fair scope.