Abstract:
Shape memory actuators for use with repetitive motion devices are provided. The present invention includes a method of urging a working end of a repetitive motion work arm into a work surface in which the working end is positioned to repetitively move across. This method may include providing a work arm having a working end positioned to repetitively move about a predetermined path of a work surface. This method may also include repetitively moving the working end of the work arm about the predetermined path of the work surface and urging the working end of the work arm into the work surface by activating a shape memory alloy actuator in physical communication with the work arm. The present invention also includes a method of urging a wiper blade towards a non-opaque surface of a motor vehicle. This may include urging a blade end of a wiper arm towards a non-opaque surface of a motor vehicle by activating a shape memory alloy actuator in physical communication with the wiper arm and moving the blade end of the wiper arm over the non-opaque surface. The present invention may also include a wiper blade system for a non-opaque surface of a motor vehicle that has a wiper arm having a blade end and a body connection end and a shape memory alloy actuator in physical communication with the body connection end.

Description:
RELATED APPLICATIONS  
       [0001]    This is a continuation of U.S. patent application Ser. No. 10/072,562, filed Feb. 11, 2002, which is a continuation of U.S. patent application Ser. No. 09/764,117, now U.S. Pat. No. 6,367,253, which is a continuation-in-part of U.S. patent application Ser. No. 09/467,749 filed Dec. 20, 1999 and entitled “Heat Converter Engine Using A Shape Memory Alloy Actuator,” now U.S. Pat. No. 6,226,992. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to shape memory alloy actuators. More particularly, the present invention regards using a shape memory alloy actuator to urge a repetitive motion device towards or into a work surface that the repetitive motion device is acting upon.  
         BACKGROUND INFORMATION  
         [0003]    A class of materials called shape memory alloys (SMA) exhibits a non-linear relationship between stress and strain when exposed to temperature changes. These alloys undergo a temperature related phase change that allows the SMA to return to any mechanical configuration imposed on the SMA when it is annealed. When the SMA is below its critical temperature, it becomes malleable and may be deformed into any arbitrary shape. Upon heating the SMA above the critical temperature, it undergoes a change in crystal structure and quickly resumes its stiff original shape. Cooling the SMA to below the critical temperature will, again, cause it to return it to the cold malleable condition allowing it to be deformed, but always returning to its original shape when it is heated above the critical temperature. The best known SMA is Nitinol, a titanium nickel alloy, having 53.5-56.5% nickel content by weight. With a temperature change of as little as 18° F., Nitinol can exert a force of as much as 60,000 psi when exerted against a resistance to changing its shape.  
           [0004]    Several prior art patents have disclosed the use of SMAs as actuators. For example, U.S. Pat. No. 4,932,210 to Julien et al. discloses the use of a shape memory alloy actuator for accurately pointing or aligning a moveable object. The SMA elements are arranged in a push-pull configuration so that one element in the activated state moves the object while another element on the opposite side in the soft state acts as a dynamic damper to prevent overtravel of the object. Similarly, U.S. Pat. No. 5,061,914 to Busch et al. discloses SMA actuators that are mechanically coupled to one or more movable elements such that the temperature induced deformation of the actuators exerts a force or generates motion of the mechanical element. However, these systems are used for precision type operations and produce little output power. These systems are not suitable for producing enough power to drive small pumps or motors, for example, a water pump in an automobile.  
           [0005]    Several prior art patents also describe the use of SMAs to drive a shaft in a motor. For example, U.S. Pat. No, 4,665,334 to Jamieson discloses a rotary stepping device having a rotatable shaft which is driven by a coiled spring clutch. An actuator made of an SMA is heated and used to pull the spring clutch to tighten it and rotate the shaft. When the SMA is cooled it returns to its malleable state and releases the spring clutch which loosens from around the shaft and returns to its original position without rotating the shaft in the opposite direction. U.S. Pat. No. 4,027,479 to Cory discloses a heat engine with an endless belt which includes a number of high density elements secured to lengths of SMA wire. The belt is attached to a pulley connected to a shaft. Two portions of the belt are maintained at different temperatures and the belt is constrained to move the elements in a continuous path into a field attracting the elements at the hot portion and out of the field at the cold portion. The SMA wire in the cold portion is stretched and the SMA wire in the hot portion contracts resulting in higher element density on the portion entering the field and thus a net force drives the belt about the pulley. However, these systems are also limited in their energy output and their complicated construction makes them impractical for use in standard machinery such as an engine or motor.  
         SUMMARY OF THE INVENTION  
         [0006]    Shape memory actuators for use with repetitive motion devices are provided. The present invention includes a method of urging a working end of a repetitive motion work arm into a work surface in which the working end is positioned to repetitively move across. This method may include providing a work arm having a working end positioned to repetitively move about a predetermined path of a work surface. This method may also include repetitively moving the working end of the work arm about the predetermined path of the work surface and urging the working end of the work arm into the work surface by activating a shape memory alloy actuator in physical communication with the work arm. The present invention also includes a method of urging a wiper blade towards a non-opaque surface of a motor vehicle. This may include urging a blade end of a wiper arm towards a non-opaque surface of a motor vehicle by activating a shape memory alloy actuator in physical communication with the wiper arm and moving the blade end of the wiper arm over the non-opaque surface. The present invention may also include a wiper blade system for a non-opaque surface of a motor vehicle that has a wiper arm having a blade end and a body connection end and a shape memory alloy actuator in physical communication with the body connection end. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 a  shows a first view of an exemplary shape memory spring (SMS) according to the present invention.  
         [0008]    [0008]FIG. 1 b  shows a first view of an exemplary shape memory spring (SMS) according to the present invention.  
         [0009]    [0009]FIG. 2 shows a first view of an exemplary heat converter engine according to the present invention.  
         [0010]    [0010]FIG. 3 shows a second view of an exemplary heat converter engine according to the present invention.  
         [0011]    [0011]FIG. 4 shows a third view of an exemplary heat converter engine according to the present invention.  
         [0012]    [0012]FIG. 5 shows a top view of an exemplary conveyor belt system for a heat converter engine according to the present invention.  
         [0013]    [0013]FIG. 6 shows an exemplary SMS assembly for a heat converter engine according to the present invention.  
         [0014]    [0014]FIG. 7 shows a detail view of an exemplary SMS assembly coupled to exemplary crank shafts in a heat converter engine according to the present invention.  
         [0015]    [0015]FIG. 8 shows an exemplary system for powering a conveyor system in a heat converter engine according to the present invention.  
         [0016]    [0016]FIG. 9 shows an exemplary system for derailing an SMS assembly coupled to crank shafts in a heat converter engine according to the present invention.  
         [0017]    [0017]FIG. 10 shows a front view of a heat converter engine according to the present invention.  
         [0018]    [0018]FIG. 11 shows an exemplary manner of applying a heating and cooling medium to a heat converter engine according to the present invention.  
         [0019]    [0019]FIG. 12 shows an exemplary heat converter engine of the present invention as an alternative power source for mechanisms in an automobile.  
         [0020]    [0020]FIG. 13 shows an alternative embodiment of a crank shaft for a heat converter engine according to the present invention.  
         [0021]    [0021]FIG. 14 a  shows a time versus speed curve for an exemplary heat converter engine having a substantially circular crank shaft according to the present invention.  
         [0022]    [0022]FIG. 14 b  shows a time versus speed curve for an exemplary heat converter engine having an alternatively shaped crank shaft according to the present invention.  
         [0023]    [0023]FIG. 15 shows an exemplary link of a flexible crank shaft for a heat converter engine according to the present invention.  
         [0024]    [0024]FIG. 16 shows an exemplary manner of coupling an exemplary SMS assembly to an exemplary link of a flexible crank shaft for a heat converter engine according to the present invention.  
         [0025]    [0025]FIG. 17 shows an alternative embodiment of a heat converter engine according to the present invention.  
         [0026]    [0026]FIG. 18 shows an alternative embodiment wherein a heat converter engine according to the present invention may be used as an electric generator.  
         [0027]    [0027]FIG. 19 shows an exemplary embodiment of an alternative actuator assembly for a heat converter engine according to the present invention.  
         [0028]    [0028]FIG. 20 a  shows a first view of an exemplary actuator arm of an exemplary embodiment of an actuator assembly for a heat converter engine according to the present invention.  
         [0029]    [0029]FIG. 20 b  shows a second view of an exemplary actuator arm of an exemplary embodiment of an actuator assembly for a heat converter engine according to the present invention.  
         [0030]    [0030]FIG. 21 a  shows a first exemplary embodiment of a hub and spoke assembly of an actuator assembly for a heat converter engine according to the present invention.  
         [0031]    [0031]FIG. 21 b  shows a second exemplary embodiment of a hub and spoke assembly of an actuator assembly for a heat converter engine according to the present invention.  
         [0032]    [0032]FIG. 22 a  shows a first exemplary embodiment of an actuator arm of an actuator assembly for a heat converter engine according to the present invention.  
         [0033]    [0033]FIG. 22 b  shows a second exemplary embodiment of an actuator arm of an actuator assembly for a heat converter engine according to the present invention.  
         [0034]    [0034]FIG. 23 shows a detail view of an actuator assembly according to the present invention.  
         [0035]    [0035]FIG. 24 shows an exemplary embodiment of a heat converter engine powered by an actuator assembly according to the present invention.  
         [0036]    [0036]FIG. 25 shows a detail view of an exemplary actuator arm from an exemplary embodiment of a heat converter engine powered by an actuator assembly according to the present invention.  
         [0037]    [0037]FIG. 26 shows an exemplary embodiment of an actuator assembly and a main case from an exemplary embodiment of a heat converter engine according to the present invention.  
         [0038]    [0038]FIG. 27 shows an exemplary embodiment of a system for heating a heating medium to be used in the present invention.  
         [0039]    [0039]FIG. 28 shows a second exemplary embodiment of an actuator assembly according to the present invention.  
         [0040]    [0040]FIG. 29 shows an aircraft landing gear in an extended position in accordance with an alternative embodiment of the present invention.  
         [0041]    [0041]FIG. 30 shows an aircraft landing gear in a semi-extended position in accordance with an alternative embodiment of the present invention.  
         [0042]    [0042]FIG. 31 shows an aircraft landing gear in a retracted position in accordance with an alternative embodiment of the present invention.  
         [0043]    [0043]FIG. 32 shows an airplane landing gear in an extended position in accordance with an alternative embodiment of the present invention.  
         [0044]    [0044]FIG. 33 shows an aircraft landing gear in an extended position under static load in accordance with an alternative embodiment of the present invention.  
         [0045]    [0045]FIG. 34 shows an aircraft landing gear in an extended airborne position in accordance with an alternative embodiment of the present invention.  
         [0046]    [0046]FIG. 35 shows an aircraft landing gear in a semi-extended position in accordance with an alternative embodiment of the present invention.  
         [0047]    [0047]FIG. 36 shows an aircraft landing gear in a retracted position in accordance with an alternative embodiment of the present invention.  
         [0048]    [0048]FIG. 37 shows a motor vehicle wiper arm and identifies the enlarged area seen in FIGS. 38 and 39.  
         [0049]    [0049]FIG. 38 shows an enlarged view of one end of a motor vehicle wiper arm in an energized state in accordance with an alternative embodiment of the present invention.  
         [0050]    [0050]FIG. 39 shows an enlarged view of one end of a motor vehicle wiper arm in a relaxed state in accordance with an alternative embodiment of the present invention.  
         [0051]    [0051]FIG. 40 shows a motor vehicle wiper arm in accordance with an alternative embodiment of the present invention.  
         [0052]    [0052]FIG. 41 shows a locking assembly in accordance with an alternative embodiment of the present invention.  
         [0053]    [0053]FIG. 42 shows a locking assembly in accordance with an alternative embodiment of the present invention.  
         [0054]    [0054]FIG. 43 shows a solar array mounted to shape memory alloy supports in accordance with an alternative embodiment of the present invention.  
         [0055]    [0055]FIG. 44 shows a solar array mounted to shape memory alloy supports in accordance with an alternative embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0056]    The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are provided with the same reference numerals. FIGS. 1 a - b  show a shape memory spring (SMS)  10  constructed of a shape memory alloy (SMA), for example, Nitinol. As described above, when an SMA is below its critical temperature, it becomes malleable and may be deformed into any shape. However, when the SMA is heated above its critical temperature the alloy undergoes a temperature related phase change allowing it to return to the mechanical configuration imposed on the material when it was annealed. FIG. 1 a  shows SMS  10  in its original compressed shape, i.e., above the SMAs critical temperature. Therefore, when the SMA of SMS  10  is heated above its critical temperature, SMS  10  returns to the compressed state as illustrated in FIG. 1 a.  FIG. 1 b  shows SMS  10  when the SMA is below its critical temperature. Because the SMA is malleable below its critical temperature, SMS  10  may be stretched, increasing its length. The purpose of this particular deformation will be described in greater detail below. Those skilled in the art will understand that this deformation is only exemplary and that it is also possible to anneal SMS  10  so that the stretched state is the original state and SMS  10  may be compressed when the SMA is malleable.  
         [0057]    [0057]FIG. 2 shows inner crank shaft carrier  20 , outer crank shaft carrier  30 , inner derail  40  and outer derail  50  according to a first embodiment of heat converter engine  15  of the present invention. Outer crank shaft carrier  30  is substantially cylindrical having raised walls  31  and  32  which form channel  33  around the circular perimeter of outer crank shaft carrier  30 . Outer derail  50  is integrally connected to outer crank shaft carrier  30  such that raised wall  31  continues around the outside perimeter of outer derail  50 . Outer derail  50  also has raised wall  51 , which, along with raised wall  31  forms channel  53  in outer derail  50 . Channel  33  of outer crank shaft carrier  30  and channel  53  of outer derail  50  form a single continuous channel through outer crank shaft carrier  30  and outer derail  50 . The purpose of this continuous channel will be described in greater detail below. Inner crank shaft carrier  20  is substantially similar in shape to outer crank shaft carrier  30 , including having channel  23 . Inner crank shaft carrier  20  is smaller and fits inside the hollow center of outer crank shaft carrier  30 . Inner derail  40  is substantially similar in shape to outer derail  50 , including having channel  43 . When inner crank shaft carrier  20  is placed inside outer crank shaft carrier  30  the inner derail  40  and outer derail  50  should be aligned so that channel  43  is substantially parallel to channel  53 . Those skilled in the art will understand that the arrangement of heat converter engine  15  shown in FIG. 2 is only exemplary and that there are other arrangements for the elements shown in this figure. For example, channel  43  of inner derail  40  may be arranged so that it faces inward towards axis  25  of inner crank shaft carrier  20  and opposes channel  53  of outer derail  50 . In this arrangement, channel  23  may be formed on the inside surface of the outer perimeter of inner crank shaft carrier  20  so that channel  23  and channel  43  form a continuous channel.  
         [0058]    [0058]FIG. 3 shows inner crank shaft  60  located on inner crank shaft carrier  20  and outer crank shaft  70  located on outer crank shaft carrier  30  added to heat converter engine  15 . Inner crank shaft  60  and outer crank shaft  70  are mounted on their respective crank shaft carriers  20  and  30  so they may rotate freely. Those skilled in the art will understand that there are numerous manners of mounting crank shafts  60  and  70  to crank shaft carriers  20  and  30 . FIG. 3 also shows another feature of interest in outer crank shaft carrier  30  and outer derail  50 . Slit  34  runs along the entire length of channel  33  in outer crank shaft carrier  30  and slit  54  runs along the entire length of channel  53  in outer derail  50 . The purpose of slits  34  and  54  will be described in greater detail below.  
         [0059]    [0059]FIG. 4 shows additional components added to heat converter engine  15 , including SMS  10  (shown in sketch form as bars), outer SMS carriers  90  and conveyor belt  100  which is coupled to conveyor belt gears  110  and  115 . The number of outer SMS carriers  90  shown in FIG. 4 is only exemplary and it should be understood that there is an outer SMS carrier  90  corresponding to each SMS  10  in heat converter engine  15 . Conveyor belt  100  is driven by conveyor belt gear  110  in the direction of arrow  116  and continuously loops around conveyor belt gears  110  and  115 . The mechanism to drive conveyor belt gear  110  will be described in greater detail below. FIG. 5 shows a top view of conveyor belt  100  which has flat inner surface  101  that comes in contact with conveyor belt gears  110  and  115  and ribbed outer surface  102 . Ribs  103  form pockets  104  on ribbed outer surface  102 . Referring back to FIG. 4, wheels  91  of outer SMS carriers  90  engage in pockets  104  of conveyor  100  as SMS carriers enter outer derail  50 , thereby coupling outer SMS carriers  90  to conveyor belt  100 . The coupling of outer SMS carriers  90  to conveyor belt  100  also causes outer SMS carriers  90  to move through channel  53  of outer derail  50  in the direction of arrow  116 . Those skilled in the art will understand that SMS carriers  90  may be coupled in other manners to conveyor  100  in such a way that the rotation of conveyor  100  is imparted to SMS carriers  90 . Those skilled in the art will also understand that there is a corresponding conveyor belt and inner SMS carriers (not shown) that move in the same direction through channel  43  of inner derail  40 .  
         [0060]    [0060]FIG. 6 shows a detail view of SMS  10 , outer SMS carrier  90  and inner SMS carrier  120 . Inner SMS carrier  120  has wheels  121 , pin guide  122  and hook  123 . Similarly outer SMS carrier  90  has wheels  91 , pin guide  92 , wedge guide  93  and a hook (not shown). First end  11  of SMS  10  is connected to hook  123  of inner SMS carrier  120  and second end  12  of SMS  10  is connected to a hook (not shown) of outer SMS carrier  90  creating SMS assembly  130 . As described with reference to FIG. 3, outer crank shaft carrier  30  and outer derail  50  may have slits  34  and  54 , respectively. The purpose of slits  34  and  54  is that as outer SMS carrier  90  of SMS assembly  130  moves through channels  33  and  53 , SMS  10  of SMS assembly  130  may project through slits  34  and  54 . Similarly, channels  23  and  43  may also have slits for the projection of SMS  10 , if channels  23  and  43  are arranged to oppose channels  33  and  53 . Throughout the figures outer and inner SMS carriers  90  and  120  are shown with varying numbers of wheels. Those skilled in the art will understand that the number of wheels is not important and the purpose of the wheels is to allow the carriers to move freely through the channels.  
         [0061]    [0061]FIG. 7 shows an exemplary manner of coupling SMS assembly  130  to inner crank shaft  60  and outer crank shaft  70 . Inner crank shaft  60  has slot  61  which engages pin guide  122  of inner SMS carrier  120 . Similarly, outer crank shaft  70  has slot  71  which engages pin guide  92  of outer SMS carrier  90 . The purpose of wedge guide  93  will be described in greater detail below. When inner SMS carrier  120  is engaged with inner crank shaft  60  and outer SMS carrier  90  is engaged with outer crank shaft  70 , SMS assembly  130  is coupled to crank shafts  60  and  70 . Thus, as crank shafts  60  and  70  rotate about their respective carriers  20  and  30 , SMS assembly  130  also rotates. As will be described in greater detail below, the action of the SMS assemblies causes the crank shafts to rotate. Those skilled in the art will understand that there are numerous manners of coupling SMS assembly  130  to crank shafts  60  and  70  and the above described manner is only exemplary. It should also be understood that crank shafts  60  and  70  may have numerous slots  61  and  71  located around the entire circumference of each crank shaft so that any number of SMS assemblies  130  may be engaged at any particular time. Also, in FIG. 7, pin guide  122  is shown on the top of inner SMS carrier  120 , whereas in FIG. 6, pin guide  122  is shown on the bottom of inner SMS carrier  120 . As described above, there are numerous possible arrangements for the elements of heat converter engine  15  and whether inner SMS carrier  120  is located inside or outside inner crank shaft  60  determines the location of guide  122 .  
         [0062]    [0062]FIG. 8 shows a cross-section of heat converter engine  15  showing a side view of inner crank shaft carrier  20 , outer crank shaft carrier  30  and the derailing area. This figure shows an exemplary arrangement for driving outer conveyor belt  100  located in outer derail  50  and inner conveyor belt  105  located in inner derail  40 . Gear  160  is coupled to inner crank shaft  60  (not shown) in any number of known manners, for example, a rotor may be attached to inner crank shaft  60  to impart rotational movement to gear  160 . The coupling of gear  160  to gear  161  imparts the rotation of inner crank shaft  60  to shaft  165  connected to gear  161 . The rotation of shaft  165  is imparted to conveyor belts  100  and  105  through conveyor belt gears  110  and  111  which are coupled to shaft  165 . Those skilled in the art will understand that gears  160  and  161  maybe selected to control the speed that SMS assemblies  130  move through the inner and outer derails  40  and  50  relative to the rotational speed of inner crank shaft  60 . The speed that SMS assemblies  130  move through inner and outer derails  40  and  50  may be determined by numerous factors including the alloy used for the SMS assembly, the cooling rate of the cooling medium, the length of the derail area, etc.  
         [0063]    [0063]FIG. 9 shows an exemplary manner of derailing SMS assembly  130  from inner crank shaft  60  and outer crank shaft  70 . Derailer  170  includes shaft  172  connected to outer derailing wheel  171  and inner derailing wheel  173 . In FIG. 9, derailer  170  is shown offset from inner and outer crank shafts  60  and  70  for illustration purposes. In operation, derailer  170  is within the boundaries of inner and outer crank shafts  60  and  70  so that outer and inner derailing wheels  171  and  173  may engage pin guides  92  and  122  of outer and inner SMS carriers  90  and  120 , respectively. The operation of derailer  170  will be described in reference to the derailment of outer SMS carrier  90 , however, it should be understood that the operation is similar for the derailment of inner SMS carrier  120 . Derailer  170  rotates about vertical axis  174  as the portion of inner and outer crank shafts  60  and  70  coupled to SMS assembly  130  move towards derailer  170 . Pin guide  92  of outer SMS carrier  90  comes into contact with outer derailing wheel  171  of derailer  170 . The rotation of derailer  170  pushes pin guide  92  out of slot  71  of outer crank shaft  70  causing SMS assembly  130  to become decoupled from outer crank shaft  70 . Those skilled in the art will understand that the shape of outer and inner derailing wheels  171  and  173  and the direction of rotation of derailer  170  is not important. The purpose of derailer  170  is to engage outer and inner SMS carriers  90  and  120  and decouple them from inner and outer crank shafts  60  and  70 . Any known mechanical or electrical means may be used to control the rotation of derailer  170 . The conveyor system and derailing operations described above may be timed with the rotation of the inner and outer crank shafts  60  and  70  (the heat converter engines RPM).  
         [0064]    An exemplary manner of operating heat converter engine  15  will be described in more detail with reference to FIGS. 4 and 10. FIG. 10 shows a front view cross-section of heat converter engine  15  showing SMS assemblies  130   a - g,  inner crank shaft  60  and outer crank shaft  70 . The rotation of crank shafts  60  and  70  coupled to SMS assemblies  130   a - g  will be described in more detail with reference to an exemplary SMS assembly. The exemplary SMS assembly may be considered to start at the position of SMS assembly  130   a,  where it has been previously heated above the critical temperature of the SMA and is in its original compressed state. Inner derail  40  and outer derail  50  (not shown) are located between the position of SMS assemblies  130   a  and  130   b.  Thus, as described above, the exemplary SMS assembly may be decoupled or derailed from inner crank shaft  60  and outer crank shaft  70  into inner derail  40  and outer derail  50  between the positions of SMS assemblies  130   a  and  130   b.  As the exemplary SMS assembly travels through the inner and outer derails  40  and  50 , the exemplary SMS assembly is cooled below its critical temperature and becomes malleable, allowing the SMS to be stretched. The cooled exemplary SMS assembly leaves the inner and outer derails  40  and  50  and re-couples with crank shafts  60  and  70  in the position of SMS assembly  130   b.  As shown in FIG. 10, the exemplary SMS assembly in the position of SMS assembly  130   b  has become stretched with respect to the original length of the SMS shown in the position of SMS assembly  130   a.  As crank shafts  60  and  70  continue to rotate in the direction of arrow  135 , the exemplary SMS assembly rotates through the positions of SMS assemblies  130   c  and  130   d  where the SMS becomes progressively longer or more stretched because it remains in its malleable state. At a predefined position of the rotation, a heating medium will begin to heat the SMS of the exemplary SMS assembly. The predetermined position for application of the heating medium may be determined by a variety of factors including the alloy used for the SMS, the heat transfer rate of the heating medium, the speed of rotation, etc. As crank shafts  60  and  70  continue to rotate in the direction of arrow  135 , the exemplary SMS assembly is heated above its critical temperature and begins to regain its original shape. The beginning of compression is when the exemplary SMS assembly is in the position of SMS assembly  130   e.  The action of the SMS assembly resuming its original shape causes a force to be exerted in the radial direction, which, in turn, causes inner crank shaft  60  and outer crank shaft  70  to rotate. Finally, as crank shafts  60  and  70  continue to rotate, the exemplary SMS assembly continues to resume its original shape as it is rotated through the positions of SMS assemblies  130   f  and  130   g  until it fully regains its original compressed state in the position of SMS assembly  130   a.  Thus, rotation of crank shafts  60  and  70  is accomplished by continuous heating and cooling of the SMS assemblies, where the force of the SMS assemblies returning to their original shape causes the crank shafts to rotate. Because each of the SMS assemblies  130   a - g  are in various states of compression, inner crank shaft  60  will not be concentric with outer crank shaft  70 . However, those skilled in the art will recognize that inner crank shaft  60 , while not centered within outer crank shaft  70 , will remain at a fixed position relative to outer crank shaft  70 .  
         [0065]    Referring back to FIG. 4, a more detailed description of the travel of the exemplary SMS assembly through the derail area will be provided. As described above, the exemplary SMS assembly may be decoupled from the inner and outer crank shafts  60  and  70  by the derailer (not shown) when the exemplary SMS assembly has been heated and regained its original compressed shape. As the exemplary SMS assembly enters the derail area, outer SMS carrier  90  may be coupled to conveyor belt  100  and inner SMS carrier (not shown) may be coupled to the conveyor belt in inner derail  40 . Also as described above, the conveyor belts rotate in the direction of arrow  115  and the exemplary SMS assembly rotates through channels  43  and  53  when it is coupled to the conveyor belts. A cooling medium is applied to the exemplary SMS assembly as it travels through the derail area to cool the SMA alloy below the critical temperature so SMS  10  becomes malleable. Those skilled in the art will understand that the exemplary SMS assembly may begin to stretch as it travels through the derail area because the distance between crank shafts  60  and  70  at the location where the exemplary SMS assembly is re-coupled to crank shafts  60  and  70  is greater than the location where the exemplary SMS assembly is decoupled from crank shafts  60  and  70 . The decoupling of the heated SMS assemblies from crank shafts  60  and  70  to be cooled in the derail area eliminates resistance against the SMS assemblies that are being heated and compressing as described above with reference to FIG. 10. The elimination of this resistance results in a more powerful and efficient heat convertor engine.  
         [0066]    [0066]FIG. 11 shows the relative positions of the application of the heating and cooling mediums to heat converter engine  15 . As described above, cooling medium  140  may be applied to the SMS assemblies (not shown) when they are located in the area of inner derail  40  and outer derail  50 . Similarly, heating medium  150  may be applied to the SMS assemblies at a predetermined position when the SMS assemblies are coupled to crank shafts  60  and  70 . Those skilled in the art will understand that any gas or liquid may be used to heat or cool the SMS assemblies, for example, air, water or a refrigerant may be used. Likewise, the heating or cooling medium may be contained in either an open system, where the heating or cooling medium is exhausted directly into the atmosphere, or in a closed system, where the heating or cooling medium may be recycled through the system. Also, the transfer of heat between the mediums and the SMS assemblies may be direct or indirect, for example, through a heat exchanger.  
         [0067]    [0067]FIG. 12 shows an exemplary use of a heat converter engine of the present invention as an alternative power source for mechanisms in an automobile. The use of a heat converter engine in on automobile may be advantageous because a heating medium (heated exhaust gas) and a cooling medium (air flow from the fan) are readily available. For example, inner crank shaft  60  may be coupled to drive shaft  65  which, in turn, is coupled to shaft  181  of transmission  180 . Rotor  182  of transmission  180  may be coupled to pulley mechanism  200  which is connected to a series of drive belts  201 - 203 . First drive belt  201  may be coupled to alternator  210 , second drive belt  202  may be coupled to power steering pump  220 , and third drive belt  203  may be coupled to air conditioning unit  230 . As described above with reference to FIGS. 4 and 10, by heating and cooling SMS assemblies  130  of heat converter engine  15 , it is possible to cause drive shaft  65 , shaft space  181  and rotor  182  to rotate. The rotation of rotor  182  may cause pulley  200  to rotate and this rotation may be imparted to each of alternator  210 , power steering pump  220  and air conditioning unit  230  by drive belts  201 - 203 , respectively. Thus, the heat converter engine may be used as an alternative power source for these devices, resulting in lowering the load on the internal combustion engine of the automobile and causing an increase in efficiency. Other examples of devices in an automobile that may be powered by this alternative power source may be water pumps, fuel pumps, etc. Those skilled in the art will understand that the pulley and drive belt system described is only exemplary, and that depending upon the application, a differential or other similar gearing may be used to impart the correct amount of power to the device using the alternative power source. Additionally, this alternative power source is not limited to automobile or motor vehicle applications, it may be used in any situation where a device may be powered by imparting mechanical rotation to the end device, or it may be used to power a generator which may produce electrical power for any consumption device. Other examples of situations where heating and cooling mediums exist are natural hot springs or power plants where cooling water is used to cool the plants components.  
         [0068]    [0068]FIG. 13 shows an alternative embodiment for outer crank shaft carrier  240  and outer crank shaft  250 . In this embodiment, outer crank shaft carrier  240  has a substantially straight section  241  connected to an arc-shaped section  242 , and outer crank shaft  250  is flexible to rotate about outer crank shaft carrier  240 . Note that the derail portion of the heat converter engine is not shown in FIG. 13. FIG. 17 shows an example of a heat converter engine including outer crank shaft carrier  240  and the derail area. A plurality of links  260  are coupled to form flexible outer crank shaft  250 . The remaining elements and operation of a heat converter engine having outer crank shaft carrier  240  and flexible outer crank shaft  250  are the same as those described above. The shape of outer crank shaft carrier  240  allows the flexible outer crank shaft  250  to rotate faster and have a more constant RPM. For example, FIG. 14 a  shows a time versus speed curve for a heat converter engine having a substantially circular outer crank shaft carrier and outer crank shaft as described with reference to FIG. 3. Whereas, FIG. 14 b  shows a time versus speed curve for a heat converter engine having the shape of outer crank shaft carrier  240  and flexible outer crank shaft  250 . As shown by these curves, a heat converter engine with the outer crank shaft carrier shaped in the form of outer crank shaft carrier  240  produces higher speeds in a shorter amount of time and provides a more linear time versus speed characteristic. Those skilled in the art will understand that each of these designs may be more efficient for any number of applications and the particular type of crank shaft will be determined by the application.  
         [0069]    [0069]FIG. 15 shows a detail view of exemplary links  260  of flexible outer crank shaft  250 . Each link  260  has first end  261 , second end  262  and middle section  263 . First end  261  has a substantially cylindrical section  264  which has hollow center  267 . Two arc-shaped surfaces  265  and  266  formed in middle section  263  are adjacent to cylindrical section  264  and have substantially the same curvature as cylindrical section  264 . Second end  262  has two substantially cylindrical sections  268  and  269  which have hollow centers  268  and  269 , respectively. Arc-shaped surface  273  formed in middle section  263  is between cylindrical sections  271  and  272  and has substantially the same curvature as cylindrical sections  271  and  272 . Slot  275  is formed in middle section  263  and will be described in greater detail below. Links  260  may be coupled by inserting cylindrical section  264  of first end  261  into arc shaped surface  273  of second end  262 . This insertion also causes cylindrical sections  268  and  269  of second end  262  to be inserted in arc shaped surfaces  265  and  266  of first end  261 . The result of this insertion is that hollow centers  267 ,  271  and  272  of cylindrical sections  264 ,  268  and  269 , respectively, form a continuous via through links  260  with a substantially uniform diameter. Connection pin  680  may be inserted into the via to couple links  260 . A plurality of links  260  may be coupled to form flexible outer crank shaft  250 .  
         [0070]    [0070]FIG. 16 shows a detail view of exemplary link  260  coupled to outer SMS carrier  90 . Link  260  has slot  275  which is a cut out having two substantially straight sections connected by an arc shaped section running from the top to the bottom of link  260 . At a predetermined distance from the top, the diameter of slot  275  is narrowed causing a ridge  276  to be formed in slot  275 . Ridge  276  is closer to the top at the edge of slot  275  and tapers to be farther away from the top as it nears the arc section of slot  275 . Outer SMS carrier  90  has pin guide  92  and wedge guide  93 . Wedge guide  93  has substantially the same shape as slot  275  and is also tapered to widen in the arc section. As SMS carrier  90  is engaged in link  260 , wedge guide  93  is seated on ridge  276  of slot  275  until the bottom of the arc section of wedge guide  93  comes into contact with the arc section of slot  275 , coupling SMS carrier  90  to link  260 . In this manner, SMS assemblies may be coupled to the outer crank shaft in heat converter engines having the shape described for outer crank shaft carrier  240  with reference to FIG. 13.  
         [0071]    [0071]FIG. 17 shows an exemplary embodiment of a heat converter engine that has storage areas  300  and  310  for broken SMS assemblies and replacement SMS assemblies. The features of the exemplary heat converter engine are the same as described above, except that inner and outer derails  40  and  50  have additional storage areas  300  and  310 . (Storage area  310  of inner derail  40  is not shown). Storage areas  300  and  310  form additional channels through which SMS assemblies may be moved. Sensor  290  senses whether an SMS assembly is in disrepair, for example, a broken SMS or carrier. Those skilled in the art will understand that there are numerous types of sensors that may be configured to detect a broken SMS or carrier, for example, a load sensor such as a spring loaded switch or a light beam sensor. When sensor  290  determines that an SMS assembly is in disrepair, it may send a signal to a derailer to derail the broken SMS assembly from outer and inner derail  40  and  50  into storage area  300  in the direction of arrow  301 . Those skilled in the art will understand that a derailer similar to the one described above may be used for this purpose. New SMS assemblies may be stored in storage area  310 , and when a broken SMS assembly is removed from outer and inner derail  40  and  50 , a new SMS assembly from storage area  310  may move into the position voided by the broken spring. The new SMS assembly may move into outer and inner derail  40  and  50  in the direction of arrows  311 . Those skilled in the art will understand that there are numerous methods of controlling the timing of moving the new SMS assembly into the position voided by the broken SMS assembly.  
         [0072]    [0072]FIG. 18 shows an exemplary arrangement wherein a heat converter engine may operate as a generator or alternator. SMS assembly  130  is shown having SMS  10 , outer SMS carrier  90  and inner SMS carrier  120 . Outer SMS carrier  90  has wheels  96  and  97  which are constructed of a magnetic material, where wheel  96  has the opposite polarity of wheel  97 . Similarly, inner SMS carrier  120  has wheels  126  and  127  constructed of a magnetic material, where wheel  126  has the opposite polarity of wheel  127 . Inner crank shaft carrier  20  has coil  26  and outer crank shaft carrier  30  has coil  36 . SMS assembly  130  travels through inner crank shaft carrier  20  and outer crank shaft carrier  30  which are both stationary. As the magnetic wheels of the outer and inner SMS carriers  90  and  120  pass through coils  26  and  36  of inner and outer crank shaft carriers  20  and  30 , the movement induces a current to flow in coils  26  and  36 . Thus, a heat converter engine rather than powering an automobiles alternator as described with respect to FIG. 12 may also serve as the alternator for an automobile.  
         [0073]    Alternative Embodiments: FIG. 19 shows an actuator assembly  401  according to a first alternative embodiment of the present invention, which includes a hub and spoke assembly  402  having hub  403  and circular spokes  404 - 409 , and actuator arms  414 - 419 . At least a portion of actuator arms  414 - 419  of actuator assembly  401  are constructed of a shape memory alloy (SMA), for example, Nitinol. Hub and spoke assembly  402  of actuator assembly  401  may be considered a crank shaft and may be constructed from any suitable material that is not an SMA, for example, metal, plastic, or rubber. Actuator assembly  401  may rotate about axis  420  of hub  403  in either direction as shown by arrow  421 . The purpose of rotating actuator assembly  401  will be described in greater detail below. Those skilled in the art will understand that the number of spokes and actuator arms shown in FIG. 19 are only exemplary and that there may be any number of spokes and actuator arms based on the particular application intended for the actuator assembly.  
         [0074]    [0074]FIGS. 20 a - b  show two different views of an exemplary actuator arm of actuator assembly  401  from FIG. 19, for example, actuator arm  414  which is constructed of an SMA. As described above, when an SMA is below its critical temperature, it becomes malleable and may be deformed into any shape. However, when the SMA is heated above its critical temperature the alloy undergoes a temperature related phase change allowing it to return to the mechanical configuration imposed on the material when it was annealed. FIG. 20 a  shows exemplary actuator arm  414  in its original shape, i.e., above the SMAs critical temperature. In FIG. 20 a,  exemplary actuator arm  414  has a first end  430  connected to second end  431  by a substantially straight middle section  432 . Therefore, when the SMA of exemplary actuator arm  414  is heated above its critical temperature, actuator arm  414  returns to the shape illustrated in FIG. 20 a.  FIG. 20 b  shows exemplary actuator arm  414  when the SMA is below its critical temperature. Because the SMA is malleable below its critical temperature, actuator arm  414  may deform into some other shape. For example, in FIG. 20 b,  middle section  432  is shown as deformed into a curved shape. Those skilled in the art will understand that this deformation is only exemplary and that when the SMA is malleable any portion of actuator arm  414  may be deformed depending on the forces acting upon actuator arm  414 . The purpose of this particular deformation will be described in greater detail below. Additionally, as shown in FIGS. 20 a  and  20   b,  the entire exemplary actuator arm  414  is constructed of an SMA. Depending on the particular purpose and use of the actuator arm, it may be possible to construct only a portion of actuator arm  414  of SMA. For example, if the only deformation required of actuator arm  414  is that shown in FIG. 20 b,  it may be possible to only construct middle section  432  of an SMA and first end  430  and second end  431  of some other material.  
         [0075]    [0075]FIG. 21 a  shows a first exemplary embodiment of hub and spoke assembly  402  of actuator assembly  401  from FIG. 19. FIG. 21 a  shows a sectional view of hub  403  and spokes  404 ,  405  and  409 . The features of the spokes will be described with respect to spoke  409 , but these features are typical for all the spokes. Spoke  404  has a generally cylindrical shape with a solid first end and an open second end which is an intake port  441  leading to hollow inside cavity  450 . Wall  445  of spoke  404  is preferably formed as a generally cylindrical surface except for a feature of interest in the present invention. Exhaust port  442  in wall  445  provides a via from hollow cavity  450  to outside of spoke  404 . Intake port  441  and exhaust port  442  may be used to conduct the flow of gas or fluid heating and/or cooling mediums to the actuator arms. Intake port  441  has a generally circular shape and exhaust port  442  has a generally rectangular shape. However, the shape of intake port  441  and exhaust port  442  is not critical, as there may be different optimum shapes for various heating and cooling mediums. As will be described in greater detail below, an intake port of an actuator arm may be positioned adjacent to exhaust port  442  so the flow of the heating or cooling medium may enter the actuator arm as it leaves spoke  404 . For example, hot air may flow into spoke  409  through intake port  441  in the direction of arrow  451  into hollow inside cavity  450  and out exhaust port  442  in the direction of arrow  452 . Those skilled in the art will understand that any gas or liquid may be used to heat or cool the actuator arms. For example, in addition to air, water or a refrigerant may be used.  
         [0076]    [0076]FIG. 22 a  shows a first exemplary embodiment of an exemplary actuator arm of actuator assembly  401  from FIG. 19, for example, actuator arm  414 . This embodiment of actuator arm  414  may be used in conjunction with the exemplary hub and spoke assembly  402  described with reference to FIG. 21 a.  As described above, actuator arm  414  is constructed of an SMA and has a first end  430  connected to a second end  431  by middle section  432 . First end  430  has intake port  460  which has the same general shape as exhaust port  442  of spoke  404  described with reference to FIG. 21 a.  When actuator arm  414  is positioned in conjunction with hub and spoke assembly  402 , intake port  460  is adjacent to exhaust port  442  of spoke  404 . Actuator arm  414  has hollow channel  461  leading from intake port  460  through the entire length of middle section  432  to exhaust port  462  in second end  431 . Intake port  460 , hollow channel  461  and exhaust port  462  allow the heating or cooling medium from hub and spoke assembly  402  to flow through the entire inside length of actuator arm  414  so that the SMA of actuator arm  414  is uniformly heated or cooled. For example, the hot air flow described above, may leave spoke  409  through exhaust port  442  and enter actuator arm  414  through intake port  460  in the direction of arrow  465 , flow through hollow channel  461  heating the SMA to above the critical temperature, causing actuator arm  414  to return to its original shape. The hot air may continue to flow through exhaust port  462  in the direction of arrow  466  to exit actuator arm  414 . Similarly, any cooling medium may also be used to cool actuator arm  414  to below its critical temperature so that it becomes malleable. Those skilled in the art will understand that the heating or cooling medium may be contained in either an open system, where the heating or cooling medium is exhausted directly into the atmosphere, or in a closed system, where the heating or cooling medium may be recycled through the system.  
         [0077]    [0077]FIG. 21 b  shows a second exemplary embodiment of hub and spoke assembly  402  of actuator assembly  401  from FIG. 19. FIG. 21 b  shows a sectional view of hub  403  and spokes  404 ,  405  and  409 . The features of the spokes will be described with respect to spoke  404 , but these features are typical for all the spokes. Spoke  404  has a generally cylindrical shape with intake port  471  in a first end which leads to first hollow cavity  473  and exhaust port  472  in a second end which leads to a second hollow cavity  474 . First hollow cavity  473  is separated from second hollow cavity  474  by a solid wall (not shown) that prevents any direct flow of heating or cooling medium between these cavities. Wall  475  of spoke  404  is preferably formed as a generally cylindrical surface except for two features of interest in the present invention. First intermediate port  476  provides a via from first hollow cavity  473  to outside of spoke  404  and second intermediate port  477  provides a via from second hollow cavity  474  to outside of spoke  404 . Intake port  471 , first intermediate port  476 , second intermediate  477  and exhaust port  472  may be used to conduct the flow of a heating or cooling medium to and from the actuator arms of the actuator assembly. As described above, the shape of ports  471 ,  472 ,  476  and  477  is not critical, as there may be different optimum shapes depending on the particular heating or cooling medium. As will be described in greater detail below, two ports of an actuator arm may be positioned adjacent to first intermediate port  476  and second intermediate port  477  so that the flow of the heating or cooling medium may enter and exit the actuator arm. For example, hot air may flow into spoke  409  through intake port  471  in the direction of arrow  481  into first hollow cavity  473  and then out first intermediate port  476  in the direction of arrow  482 . When the flow leaves first intermediate port  476  it enters a port of an actuator arm that is adjacent to first intermediate port  476 . The flow of the heating or cooling medium through the actuator arm will be described in greater detail below. The flow leaves the actuator arm through a port that is positioned adjacent to second intermediate port  477 . The flow leaving the actuator arm will enter second intermediate port  477  in the direction of arrow  483  into second hollow cavity  474  and out of spoke  404  through exhaust port  472  in the direction of arrow  484 .  
         [0078]    [0078]FIG. 22 b  shows a second exemplary embodiment of an exemplary actuator arm of actuator assembly  401  from FIG. 19, for example, actuator arm  414 . This embodiment of actuator arm  414  may be used in conjunction with the exemplary hub and spoke assembly  402  described with reference to FIG. 21 b.  As described above, actuator arm  414  is constructed of an SMA and has first end  430  connected to second end  431  by middle section  432 . First end  430  has intake port  490  which has the same general shape as first intermediate port  476  of spoke  404 , as described with reference to FIG. 4 b.  First end  430  also has exhaust port  491  which has the same general shape as second intermediate port  477  of spoke  404 , as described with reference to FIG. 21 b.  When actuator arm  414  is positioned in conjunction with hub and spoke assembly  402 , intake port  490  is adjacent to first intermediate port  476  of spoke  404  and exhaust port  491  is adjacent to second intermediate port  477 . Actuator arm  414  has a hollow channel  493  which has a first section  501  running from intake port  490  through middle section  432  towards second end  431 . Prior to entering second end  431 , hollow channel  493  has a second section  502  that is at substantially a right angle to first section  501 . A third section  503  of hollow channel  493  is at substantially a right angle to second section  502  and runs to exhaust port  491 . Those skilled in the art will understand that the shape of hollow channel  493  is not important, the importance of hollow channel  493  is that it delivers the flow of the heating or cooling medium to the SMA portion of actuator arm  414  so that it may be uniformly heated or cooled. For example, the hot air flow described above with reference to FIG. 21 b,  may leave spoke  409  through first intermediate port  476  and enter actuator arm  414  through intake port  490  in the direction of arrow  506 , flow through channel  493  heating the SMA to above its critical temperature and causing actuator arm  404  to return to its original shape. The hot air may continue to flow through exhaust port  491  in the direction of arrow  407 , exiting actuator arm  414  and reentering spoke  409  through second intermediate port  477 .  
         [0079]    [0079]FIG. 23 shows an exemplary manner of attaching the actuator arms to the hub and spoke assembly. In this embodiment, first end  430  of exemplary actuator arm  419  is constructed in a circular shape so that the first end  430  fits into circular cavity  510  formed by spokes  404  and  409 . This construction assures that actuator arms  414 - 419  are not separated from hub and spoke assembly  402  in the radial direction as actuator assembly  401  rotates about axis  420  of hub  403 , as described with reference to FIG. 19. As will be described in greater detail below, actuator assembly  401  may be inserted into a case to prevent actuator arms  414 - 419  from separating from hub and spoke assembly  402  in the axial direction. This construction allows for easy insertion and removal of actuator arms by moving first end  430  in the axial direction into and out of cavity  510 . In this embodiment, exhaust port  442  of spoke  404  is adjacent to intake port  460  of actuator arm  419 , as described with reference to FIGS. 21 a  and  22   a,  respectively. Similarly, this embodiment allows first intermediate port  476  of spoke  404  to be adjacent to intake port  490  of actuator arm  419  and second intermediate port  477  of spoke  404  to be adjacent to exhaust port  491  of actuator arm  419 , as described with reference to FIGS. 21 b  and  22   b.  Those skilled in the art will understand that there are many possible manners of connecting the actuator arms to the hub and spoke assembly, for example, through the use of other integrally formed shapes or by using mechanical fasteners. In addition, it is possible to form the hub in such a manner that the actuator arms may be connected directly to the hub such that spokes are not necessary.  
         [0080]    [0080]FIG. 24 shows an exemplary embodiment of heat converter engine  600  powered by an exemplary actuator assembly of the present invention. Heat converter engine  600  includes actuator assembly  610  which is positioned inside main case  620 . First end  631  of drive shaft  630  is inserted through opening  611  in actuator assembly  610  and opening  622  in main case  620 . Drive shaft  630  is coupled with shaft  641  of transmission  640  through first sealed bearing  650 . Second sealed bearing  651  is coupled to second end  632  of drive shaft  630  so that drive shaft  630  may rotate freely. Insertion of drive shaft  630  through opening  611  in actuator assembly  610  rigidly couples drive shaft  630  to actuator assembly  610  so that as actuator assembly  610  rotates inside main case  620 , this rotation is imparted to drive shaft  630 . Coupling of drive shaft  630  and actuator assembly  610  may be accomplished by any conventional means. The action that drives the rotation of actuator assembly  610  will be described in greater detail below. Actuator assembly  610  is sealed within main case  620  by cover  660 . As described above, cover  660  prevents the actuator arms of actuator assembly  610 , for example actuator arm  614 , from separating from hub and spoke assembly  613  in the axial direction. A heating medium intake  670  and a cooling medium intake  680  are connected to cover  660  which has two vias (not shown) to allow the heating and cooling mediums to enter the area of main case  620  when engine  600  is sealed.  
         [0081]    [0081]FIG. 25 shows a detail view of exemplary actuator arm  616  of actuator assembly  610  from FIG. 24. This sectional view shows second end  431  of actuator arm  616  that comes in contact with inside cylindrical wall  621  of main case  620  as shown in FIG. 24. Second end  431  of actuator arm  616  has two sealed bearings  655  and  656 . As actuator assembly  610  rotates within main case  620 , sealed bearings  655  and  656  come in contact with inside wall  621  and allow actuator assembly  610  to rotate freely within main case  620 . Those skilled in the art will understand that this is only an exemplary embodiment of the portion of the actuator assembly that comes in contact with the main case and that there are numerous manners of constructing the actuator assembly or the main case such that the actuator assembly will rotate freely while in contact with the inside wall of the main case.  
         [0082]    Referring back to FIG. 24, an exemplary manner of causing actuator assembly  610  to rotate within main case  620  is the following: A cooling medium is input through cooling medium intake  680 . The via in cover  660  which allows the cooling medium to enter the area of main case  620  is positioned so that the cooling medium will enter an intake port of hub and spoke assembly  613  of actuator assembly  610 , for example, intake port  441  as described with reference to FIG. 21 a.  The cooling medium will then flow through hub and spoke assembly  613  and into actuator arms  614 - 619 , cooling actuator arms  614 - 619  below the critical temperature of the SMA, causing actuator arms  614 - 219  to become malleable and able to be deformed from their original shape. As actuator assembly  610  rotates inside main case  620 , only one intake port of a spoke will be positioned adjacent to the via at each instant of time. Thus, cooling medium intake  680 , the via and the intake port of the spoke should be sized so that during the single pass in each rotation, enough cooling medium may flow into the actuator arm to cool it below its critical temperature. However, those skilled in the art will understand that it may be possible to design an actuator assembly where each actuator arm does not need to be cooled to below its critical temperature during each rotation of the actuator assembly.  
         [0083]    In this embodiment, the original shape of actuator arms  614 - 619  is substantially straight as shown in FIG. 24. When the actuator arms are malleable, the force exerted on the arms by coming in contact with inside wall  621  of main case  620  will cause a curvature to be formed in actuator arms  614 - 619 , as described with reference to FIG. 20 b.  Those skilled in the art will understand that, in operation, all of actuator arms  614 - 619  of actuator assembly  610  will not simultaneously be in their original shape as shown in FIG. 24. Some of the arms may be cooled to below the critical temperature of the SMA and have the curved shape described above. In this embodiment, opening  611  of actuator assembly  610  will not be centered with respect to main case  620 . For example, with reference to FIG. 26, actuator assembly  610  is shown inserted into main case  620 . As shown, actuator arms  617  and  618  are in their original substantially straight shape, actuator arms  616  and  619  have a slight curvature from the force exerted on these arms from inside wall  621  of main case  620 , and actuator arms  614  and  615  have the greatest curvature. Thus, opening  611  in hub and spoke assembly  613  of actuator assembly  610  is not centered in main case  620  because of the varying degrees of curvature on actuator arms  614 - 619 . However, those skilled in the art will recognize that opening  611 , while not centered within main case  620 , will remain at a fixed position while actuator assembly  610  rotates. For example, as actuator assembly  610  rotates, actuator arms  617  and  618  that are shown in their original substantially straight shape will be cooled to below their critical temperature and the force exerted by inside wall  621  of main case  620  will cause these actuator arms to become curved. At the same time, actuator arms  614  and  615  that are in the fully curved shape will be heated above the critical temperature causing these actuator arms to return to their original substantially straight shape. When this occurs the position of actuator arms  614  and  615  will essentially be interchanged with the position of actuator arms  617  and  618 , respectively. Thus, actuator assembly  610  will have rotated one half rotation, but the axis of rotation about opening  611  will not change. To account for this offset of the axis of rotation from the center of main case  620 , opening  622  of main case  620  may be offset from center to be in line with opening  611  of actuator assembly  610 .  
         [0084]    Again referring back to FIG. 24, when the cooling medium is exhausted from the actuator arm, it flows out of main case  620  through exhaust port  623 . Hub and spoke assembly  613  and actuator arms  614 - 619  may be similar to those described with reference to FIGS. 21 a  and  22   a,  where the heating or cooling medium is exhausted from the actuator assembly through an exhaust port on the actuator arm. For example, exhaust port  62  of actuator arm  414  in FIG. 22 a.  Those skilled in the art will understand that hub and spoke assembly  613  and actuator arms  614 - 619  may also be similar to those described with reference to FIGS. 21 b  and  22   b,  where the heating or cooling medium is exhausted from the hub and spoke assembly rather than the actuator arm. For example, exhaust port  472  of the hub and spoke assembly in FIG. 21 b.  In this case, exhaust ports  623  and  624  of main case  620  may be placed in a different position to accommodate the exhaust of the heating or cooling medium.  
         [0085]    Similar to the intake of the cooling medium, a heating medium is input through heating medium intake  670 . The via in cover  660  which allows the heating medium to enter the area of main case  620  is also positioned so that the heating medium will enter an intake port of the hub and spoke assembly  613  of actuator assembly  610 , for example, intake port  441  as described with reference to FIG. 21 a.  The heating medium will then flow through hub and spoke assembly  613  and into actuator arms  614 - 619 , heating the actuator arms above the critical temperature of the SMA and causing the actuator arms to resume their original shape. As the actuator arms return to their original substantially straight shape, the force exerted by the actuator arms in the radial direction against inside wall  621  of main case  620  will cause the entire actuator assembly to rotate. Concurrently, the rigidity of the actuator arms that are above the critical temperature will cause the actuator arms that are below the critical temperature to be deformed into the curved shape by being forced against inside wall  621  of main case  620 . The complete action of rotation will be described in more detail below. Also, as described above, the heating medium may be exhausted from main case  620  through exhaust port  624 .  
         [0086]    Referring back to FIG. 26, the rotation of actuator assembly  610  within main case  620  will be described in more detail with reference to an exemplary actuator arm. The exemplary actuator arm may be considered to start at the position of actuator arm  617 , where it has been previously heated above the critical temperature of the SMA and is in its original substantially straight shape. As actuator assembly  610  rotates in the direction of arrow  625 , the intake port of the spoke that distributes the heating and cooling medium to the exemplary actuator arm, for example, intake port  691  of spoke  697  for actuator arm  617 , aligns with the via allowing the cooling medium to flow into the spoke. The spoke distributes the cooling medium flow to the exemplary actuator arm, for example, in the manners described above with reference to FIGS. 21 a - b  and  22   a - b.  As described above, the via and intake port should be sized so that a sufficient amount of cooling medium flows into the spoke while the via and intake port are aligned to cool the exemplary actuator arm below its critical temperature. As actuator assembly  610  continues to rotate in the direction of arrow  625 , the exemplary actuator arm rotates into the position of actuator arm  618 . In this position, the cooling medium is cooling the actuator arm, but it is not yet below the critical temperature, therefore, the exemplary actuator arm remains in its substantially straight original shape. When the exemplary actuator arm is in the position of actuator arms  617  and  618 , it is rigid and exerts force in the radial direction against inside wall  621  of main case  620 . Concurrently, this rigidity forces actuator arms opposite those in the positions of actuator arms  617  and  618 , for example, actuator arms  614  and  615  to be deformed into a curved shape to account for the rigidity. As actuator assembly  610  continues to rotate in the direction of arrow  625 , the exemplary actuator arm moves into the position of actuator arm  619 . Between the positions of actuator arm  618  and  619 , the cooling medium has cooled the exemplary actuator arm to below the critical temperature so that, when the exemplary actuator arm reaches the position of actuator arm  619  it is beginning to be deformed into the curved shape. Actuator assembly  610  continues to rotate in the direction of arrow  625  and the exemplary actuator arm rotates into the position of actuator arm  614 , where the force exerted by a rigid actuator arm in the position of actuator arm  617  through hub and spoke assembly  613  causes the exemplary actuator arm to be deformed into the greatest curvature.  
         [0087]    Continued rotation of actuator assembly  610  in the direction of arrow  625  causes the intake port of the spoke that distributes the heating and cooling medium to the exemplary actuator arm, for example intake port  692  of spoke  694  for actuator arm  614 , to align with the via allowing the heating medium to flow into the spoke and then be distributed to the exemplary actuator arm. Again, the via and the intake port should be sized so that a sufficient amount of heating medium enters the spoke while the intake port and via are aligned to heat the exemplary actuator arm above the critical temperature. As actuator assembly  610  continues to rotate in the direction of arrow  625 , the exemplary actuator arm rotates into the position of actuator arm  615  where the heating medium has not yet heated the exemplary actuator arm above the critical temperature. The exemplary actuator arm remains in the position of greatest curvature because of the force exerted by a rigid actuator arm in the position of actuator arm  618 . Continued rotation of actuator assembly  610  causes the exemplary actuator arm to move between the position of actuator arms  615  and  616 , where the heating medium has heated the exemplary actuator arm above the critical temperature so that the exemplary actuator arm begins to return to its original shape. The action of the actuator arm resuming it original shape causes a force to be exerted in the radial direction against inside wall  621  of main case  620 , which, in turn, causes actuator assembly  610  to rotate. Finally, as actuator assembly  610  continues to rotate, the exemplary actuator arm resumes its original shape when it reaches the position of actuator arm  617 .  
         [0088]    Thus, rotation of actuator assembly  610  is accomplished by continuous heating and cooling of actuator arms  614 - 619 , where the force of the actuator arms returning to their original shape causes the entire assembly to rotate. Those skilled in the art will understand that the original and deformed shapes described above, i.e., straight and curved, are only exemplary and that other shapes may also be used for the actuator arms to accomplish the same action of causing the actuator assembly to rotate. Referring back to FIG. 24, the rotation of actuator assembly  610  also causes drive shaft  630  to rotate which, in turn, causes shaft  641  of transmission  640  to rotate. Through internal gearing in transmission  640 , the rotation of shaft  641  is imparted to rotor  642  of transmission  640 . The rotation of rotor  642  may be used to drive or power any number of mechanisms.  
         [0089]    [0089]FIG. 27 shows an exemplary embodiment of a system for heating and delivering a heating medium to the intake of the heat converter engine. FIG. 27 shows exhaust manifold  700  having intake ports  701 - 704 , main header  705  and exhaust port  706 . Hot exhaust air from the cylinders of an internal combustion engine enters intake ports  701 - 704  in the direction of arrows  711 - 714 , flows through main header  705  in the direction of arrow  715  and out exhaust port  706  in the direction of arrow  716 . In addition to exhaust manifold  700 , this exemplary embodiment also has medium delivery system  720 , having an intake port  721 , pump  722 , heating coil  723  and exhaust port  724 . A liquid heating medium enters medium delivery system  720  through intake port  721  and is pumped in the direction of arrow  731  by pump  722 . The heating medium entering medium delivery system  720  is cool, or at least not heated to its ideal temperature. As shown in FIG. 27, at point  735 , medium delivery system  720  enters the boundary of exhaust manifold  700  in the area of main header  705 . In this area, medium delivery system  720  has heating coil  723 . As the heating medium flows through heating coil  723 , the flow of hot exhaust air in header  705  heats the heating medium in heating coil  723  to its ideal temperature. Medium delivery system  720  then exits the boundary of exhaust manifold  700  at point  736  and the heated heating medium flows in the direction of arrow  734  out exhaust port  724  of medium delivery system  720 . The heating medium may then be delivered to the heating medium intake of the heat converter engine, for example heating medium intake  670  of FIG. 24.  
         [0090]    Medium delivery system  720  may also be adapted for use by a gaseous heating medium by simply using a fan in place of pump  722  to cause gas flow through the system. Alternatively, it may also be possible to use the hot exhaust flow from exhaust manifold  700  as a direct input to the heating medium intake of the heat converter engine, thereby eliminating medium delivery system  700 . Similarly, it may also be possible to have a medium delivery system for delivering the cooling medium to the cooling medium intake of the heat converter engine, for example cooling medium intake  680  of FIG. 24. For example, the flow of cooling medium may be cooled by a compressor/condenser unit prior to entering the cooling medium intake. An interesting feature of the cooling medium delivery system may be that the compressor/condenser unit may be powered by the heat converter engine, after initial start-up, thereby allowing the entire system to be self-contained.  
         [0091]    [0091]FIG. 28 shows a first alternative embodiment of an SMA actuator assembly of the present invention. Actuator assembly  800  has hub and spoke assembly  501  and actuator arms  802 - 805  and is positioned within main case  810 . Each of actuator arms  802 - 805  is constructed of an SMA and has a first end  821  for coupling with hub and spoke assembly  801  and a second end  822  having sealed bearing  823  that comes in contact with the inside wall  811  of main case  810 , allowing actuator assembly  800  to freely rotate within main case  810 . Actuator assembly  800  operates in the same manner as the previously described actuator assembly in that the rotation of actuator assembly  800  within main case  810  is caused by continuous heating and cooling of actuator arms  802 - 805 . When actuator arms  802 - 805  are cooled they become malleable and are deformed into the curved shape as shown by actuator arms  802 - 804 , with actuator arm  803  having the greatest degree of curvature. As actuator arms  802 - 805  are heated, they resume their original substantially straight shape, as shown by actuator arm  805 . As described above, this action of actuator arms  802 - 805  resuming their original shape causes a force to be exerted in the radial direction causing actuator assembly  800  to rotate within main case  810 .  
         [0092]    In this embodiment, actuator arms  805 - 805  are heated and cooled by direct application of the heating and cooling mediums to the exterior of actuator arms  802 - 805 . Main case  810  has a hot gas port  812  and a cold gas port  813  which effect the operation of actuator assembly  800  as follows: An actuator arm in the position of actuator arm  805  has been heated and is in its original substantially straight shape. As actuator assembly  800  rotates in the direction of arrow  830 , the actuator arm crosses the boundary  814  of cold gas port  813  and an incoming stream of cold gas flows over the actuator arm cooling it below the critical temperature of the SMA. By the time the actuator arm is cooled below the critical temperature, it has rotated into the position of actuator arm  802  and has started to deform into the curved shape. As actuator assembly  800  continues to rotate in the direction of arrow  830  the actuator arm is further deformed into a more pronounced curvature that coincides with boundary  815  of cold gas port  813 . Actuator assembly  800  continues to rotate in the direction of arrow  830  and the actuator arm crosses boundary  816  of hot gas port  812  into the position as shown by actuator arm  803 . In this position, an incoming stream of hot gas flows over the actuator arm heating it above the critical temperature of the SMA. By the time actuator assembly  800  has rotated in the direction of arrow  830  so that the actuator arm has reached the position as shown by actuator arm  804 , it is heated above the critical temperature and is beginning to resume its original shape. The actuator arm continues to rotate in the direction of arrow  830  until it has fully regained its original shape as shown by actuator arm  805 . This embodiment of the actuator assembly and main case may be used in an heat converter engine similar to the one described with reference to FIG. 24.  
         [0093]    [0093]FIGS. 29-31 provide a side view of an aircraft landing gear  290 , as may be embodied in an alternative embodiment of the present invention. In these figures, a Shape Memory Spring (SMS) strut  293 , a locking latch  291 , a nitrogen filed shock absorber  297 , a retracting strut  295 , a tire  296 , and a locking spring  294  are shown. FIG. 29 illustrates the landing gear  290  in a fully deployed position, FIG. 30 shows the landing gear in a semi-retracted position and FIG. 31 shows the landing gear in a fully retracted position. The aircraft landing gear  290  in this embodiment may be employed in the nose of large aircraft and as the main landing gear of lighter aircraft. Exemplary aircraft include airplanes, helicopters, gliders, as well as all others that employ retractable landing gear.  
         [0094]    The landing gear  290  may be deployed and locked in an extended position during takeoff and landing and may be raised during flight in a retracted, folded, and stowed away position. In this embodiment, the gear may be raised by elongating the SMS strut  293 . Then, once the landing gear  290  is fully retracted, it may be locked in place by the locking latch  291 .  
         [0095]    In this embodiment the SMS strut  293  may contain a shape memory alloy (SMA) that expands when heated and contracts when cooled. This shape memory alloy may be sized to develop the required forces necessary to raise the landing gear  290 . For example, the cross-sectional area may be sized to be able to develop forces greater than two times those necessary to raise the landing gear. This level of force is preferred in this embodiment in order to provide for a safety factor and also in order to overcome other dynamic forces encountered shortly after takeoff that may impede the retraction of the landing gear. Similarly, the length of the shape memory alloy may also be sized such that the distance of travel of the landing gear is closely correlated to the distance of maximum expansion of the shape memory alloy. In other words, when the shape memory alloy within the SMS strut  293  is activated its maximum distance of expansion may be 20% greater than the maximum distance required to fully retract the landing gear  290  into the aircraft&#39;s fuselage. By considering the maximum length of the SMA, the forces placed on the landing gear, while the SMS strut is active and the landing gear  290  is in its retracted position, can be controlled.  
         [0096]    The SMS alloy, resident within the SMS strut  292 , may be heated by various methods including passing an electrical current through it, by positioning it near a heat generating resistor or by passing thermally charged fluids over and around it. These sources of heat may communicate with the SMS strut via a shape memory spring strut activation line (not shown). In each case and in the various other plausible methods of heating the shape memory alloy, as the shape memory alloy is heated it will expand and, acting through the various members and linkages of the landing gear, cause the landing gear to retract. Once locked in the retracted position, via a locking hatch or other apparatus, the shape memory alloy may be allowed to cool. Once cooled, the SMA will no longer place a lifting force on the landing gear. Thus, in the retracted state the landing gear is maintained in a folded position via the locking latch  291 . When required, the landing gear  290  may be lowered by unlocking the locking latch  291  and allowing gravitational and locking spring  294  forces to lower it. The locking latch  291  may be unlocked by pulling on chord  292  although numerous other embodiments are also plausible for releasing the landing gear including the use of additional SMAs, SMSs, locking solenoids or other locking mechanisms. Once released and free to move, forces generated by spring  294  may supplement the gravitational forces that will urge the landing gear  290  back into its fully deployed and locked position.  
         [0097]    [0097]FIG. 32 is a side view of the landing gear employing an SMS strut activated by an internal shape memory alloy as installed in a nose landing gear of a light passenger airplane. FIG. 32 contains the nose  320  of a light passenger airplane, an SMS strut  325 , a nitrogen filled shock absorber  322 , a retracting strut  324 , and a locking spring  323 . It also illustrates a line of travel of the landing gear with dashed line  321 . As can be seen in FIG. 32 the line of travel  321  creates an arc like curve in this embodiment.  
         [0098]    In addition to the embodiments described above, numerous other embodiments are also plausible to facilitate the raising and lowering of aircraft landing gear. For example, the struts and springs may be reconfigured such that the contraction of SMS strut generates the required forces to raise the landing gear. Furthermore, rather than using electrical currents to facilitate the expansion of the struts other sources of thermal energy may be employed. For example heated air may be forced across the shape memory alloy in the strut to cause it to expand in a different embodiment, likewise other fluids, such as water or oil may be used to heat the shape memory alloy. Moreover, in these embodiments, a shape memory spring strut activation line (not shown) may be in fluid communication with a pump that urges these compressible and non-compressible fluids towards the SMA. Once the fluids reach the SMA it will expand in reaction to the thermal energy transferred by the fluid.  
         [0099]    [0099]FIGS. 33-36 show a landing gear as may be employed in a larger aircraft. FIG. 33 shows the landing gear  330  in a fully deployed position under static load; FIG. 34 shows the landing gear  330  in a fully deployed position when the aircraft is airborne; FIG. 35 shows the landing gear  330  in a partially retracted position; and, FIG. 36 shows the landing gear  330  in a fully retracted position. As described above, the landing gear contains an SMS strut  331  that generates the lifting force to lift the undercarriage via the expansion of the shape memory alloy resident within it. Like the embodiment described above, the shape memory alloy may be activated through various heat introduction methodologies including electrical current and thermal transfer fluids. In this embodiment, rather than having a locking mechanism hold the gear in a retracted position the SMS strut is activated throughout the entire flight time to keep the landing gear retracted. Then, when necessary, the shape memory alloy is allowed to cool and, thus, allow the landing gear to retract back down into a locked position.  
         [0100]    [0100]FIG. 37 is a profile view of a windshield wiper arm as may be employed by a motor vehicle such as a motorcycle, a motor boat, and an automobile in accord with an alternative embodiment of the present invention. During high speeds the airflow over the windshield of a motor vehicle (not shown) may lift the wiper blade  370  off of the glass and thereby reduce the wiper blade&#39;s  370  effectiveness. In order to overcome these high speed lifting forces, a downward force, opposing the lifting force, may be generated to hold the wiper blade  370  against the glass.  
         [0101]    [0101]FIG. 38 is an enlarged view of the circled area in FIG. 37. In FIG. 38 the SMS coil  383  is shown in an energized state. Clearly evident in FIG. 38 are the wiper arm head  388 , pivot pin  385 , wiper blade pin  386 , wiper arm  381 , wiper blade connection  387 , reaction arrow  380 , rotation arrows  3800 , force arrow  384 , power supply line  382 , SMS coil  383 , and chassis  389 .  
         [0102]    [0102]FIG. 39 also provides an enlarged view of the circled area in FIG. 37. In FIG. 39 the SMS coil  383  is shown in a relaxed state. In FIG. 39, as the SMS coil  383  is shown in a relaxed state, the reaction arrow  391 , rotation arrows  390 , and force arrow  392  are opposite those in FIG. 38.  
         [0103]    In use, in order to create an additional inward force by the wiper arm  381  against the windscreen once the motor vehicle has reached a minimum target speed, an electrical voltage may be applied to heating element  3810  in order to heat SMS coil  383 . Upon being heated, the SMS coil  383 , which contains an SMA, will expand and begin to place a force on the rocker arm  3820 . The direction of this force is illustrated by arrow  384 . This force causes the rocker arm  3820  to rotate as shown by rotation arrows  3800 . As the rocker arm  3820  rotates a reaction force illustrated by reaction arrow  380  is generated. This reaction force urges the wiper blades into the windscreen and thus creates a greater contact force between the wiper blades (not shown) and the windscreen (not shown). Then, as the vehicle slows or the additional forces are no longer needed, the voltage will be removed and the SMS coil  383  may be allowed to relax back to its original length. No longer exerting a force against the rocker arm  3820 , the arm will rotate back to its relaxed position under biasing forces generated by springs which are not shown.  
         [0104]    Rather than using a heating coil  3810  to generate the thermal energy that will facilitate the expansion of the SMS coil  383 , other methods of heating the SMS coil may also be employed. These methods include placing a voltage source directly in contact with the SMS coil  383  and allowing its internal electrical resistance to generate the heat needed to enlarge the coil or forcing thermal conduction fluid over and in contact with the SMS coil to provide the requisite thermal energy. The thermal conduction fluid may be engine oil pumped from the crank case and regulated by a valve controlled by a processor in the motor vehicle.  
         [0105]    [0105]FIG. 40 provides an alternative embodiment wherein rather than pushing up on a rocker arm as described above, an SMS coil is placed within the wiper arm head to facilitate the urging of the wiper blades against the glass. In this embodiment, when additional inward force is required to keep the wiper blade against the glass, the SMS coil  403  may be heated via an electrical line, thereby causing it to shrink and create an additional inward force.  
         [0106]    [0106]FIGS. 41-42 provide a side view of an automobile power door lock assembly  413  in accord with another alternative embodiment of the present invention. These door locking assemblies  413  contain a locking head  411 , an SMS coil  412 , and a bushing  415 . The SMS coil  412  may be used to slide the locking head  411  back and forth as indicated by arrows  414 . The SMS coil  412  may be activated by applying a voltage to it or otherwise heating it. Upon being heated the SMS coil  412  may expand and urge the locking head  411  into one position. Once the heat is removed from the SMS coil  412  a biasing force generated by the bushing  415  may urge the locking head  411  back to its original position. Alternatively, in another embodiment, two SMS coils may be used to move the locking head back and forth. In this alternative embodiment an ongoing current need not be sustained to maintain the SMS coil in an extended position to resist the biasing force of the bushing.  
         [0107]    [0107]FIG. 43 provides a moveable solar array in accord with another alternative embodiment of the present invention. In this embodiment a solar array  431  is pivotably mounted on a frame  433  and is moveable via SMS coils  432 . These SMS coils are in optical communication with focusing lenses  435 . These focusing lenses may be positioned as to focus the ambient rays of the sun onto the SMS coils  432 . These focusing lenses  435  and SMS coils  432  work in unison with each other to rotate the face of the solar array in conjunction with the movement of the Sun caused by the Earth&#39;s rotation. As the Sun moves across the sky its rays will non-uniformly heat the various SMS coils  432  supporting the solar array. Thus, the SMS coils that receive more of the Sun&#39;s rays will be heated to a greater degree and will shrink, thereby pulling the face of the solar array towards the Sun. Then, as the Sun moves across the sky, its rays will reach the SMS coils  432  in increasing and decreasing intensities causing the face of the array to rotate and track it across the sky. In short, when one SMS coil  432  receives more light its downward forces will increase while another SMS coil  432  will receive less light, thereby reducing its downward pulling forces.  
         [0108]    The focusing lenses  435  may be used to increase the intensity of the radiant energy reaching the coils. Alternatively, when the amount of light reaching the solar array is large enough, as may be the case in ceratin equatorial regions or in outer space, the focusing lenses may not be needed.  
         [0109]    [0109]FIG. 44 provides an alternative embodiment wherein the focusing lenses  435  have not been employed as may be used in a self-adjusting satellite solar array.