Abstract:
An actuator that is capable of taking a relatively small amount of force or displacement input therein and of outputting a relatively large amount of force or displacement. The actuator includes a translating component and a plurality of levers or arms. The increase in force or displacement is achieved by adequately selecting the relative lengths of and positioning the levers or arms. Also, an actuation method for transforming an input of a relatively small amount of force or displacement into an output of a relatively large amount of force or displacement.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to the provisional U.S. patent application entitled, “Dual Cable Release Actuator,” filed Oct. 27, 2004, having a Ser. No. 60/622,462, now pending, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to actuators and to actuation methods. More particularly, the present invention relates to actuators and actuation methods configured to output a force and/or amount of displacement that is different from an input force and/or amount of displacement. 
     BACKGROUND OF THE INVENTION 
     Currently-available actuators are implemented in a variety of mechanical and electromechanical systems. However, currently-available actuators that have relatively small amounts force and/or displacement input into them are not amenable to being included in devices or systems that would require the actuator to output a relatively large amount of force and/or displacement (i.e., travel). 
     For example, currently-available actuators are often connected to push buttons and are engaged when a user depresses the push button a relatively short distance and with a relatively small amount of force. Pursuant to being engaged, these currently-available actuators are only capable of outputting a relatively small amount of force and displacement. Therefore, they cannot be incorporated in devices and systems where a large amount of force or displacement is needed. 
     One example of a device or system where a currently-available actuator would not be suitable is in a removable cover for a pick-up truck bed. Such a cover, instead of having one or more actuators incorporated therein, make use of handles and/or levers to release hooks that attach the cover to the sides of the pick-up bed. Unfortunately, the levers and/or handles are relatively large, bulky and expensive. Therefore, the cover itself is also relatively large, bulky and expensive. In addition, frail or injured persons may have difficulty applying enough force to the handles and/or levers to release the cover from the truck bed to which it is attached. 
     At least in view of the above, it would be desirable to provide actuators that output a relatively large amount of force or displacement pursuant to being engaged with a relatively small amount of force or displacement. In addition, it would be desirable to provide actuation methods that output a relatively large amount of force or displacement pursuant to a relatively small amount of force or displacement being input. 
     SUMMARY OF THE INVENTION 
     At least some of the foregoing needs are met by a first embodiment of the present invention, wherein an actuator is provided. The actuator includes an input connection configured to be connected to a user interface. The actuator also includes a first output connection connected to the input connection. In addition, the actuator also includes a translating component connected to the input connection and configured to translate between a primary position and a secondary position upon the user interface being engaged. The actuator further includes a primary lever communicating with the translating component. The primary lever is configured to rotate when the translating component translates between the primary position and the secondary position. The actuator also includes a secondary lever that is offset from and fixedly connected to the primary lever. The secondary lever is connected to the first output connection. The secondary lever is also configured to rotate when the primary lever rotates. In addition, the primary lever has a first length and the secondary lever has a second length. 
     According to another embodiment of the present invention, a method of actuating a system is provided. The method includes engaging a user interface. The method also includes translating a first component between a primary position and a secondary position upon the user interface being engaged. The method further includes rotating a primary lever upon the translating component translating. The method also includes rotating a secondary lever upon the primary lever rotating. Also, the secondary lever is offset from and fixedly connected to the primary lever. 
     According to yet another embodiment of the present invention, another actuator is provided. This actuator includes first connecting means for connecting to a user interface. This actuator also includes second connecting means for connecting to an output and is connected to the first connecting means. This actuator further includes translating means for translating between a primary position and a secondary position upon the user interface being engaged. In this actuator, the translating means is connected to the first connecting means. This actuator also includes first rotating means for rotating about an axis. In this actuator, the first rotating means extends between the translating means and the axis. Also, the first rotating means is configured to rotate about the axis upon the translating means translating between the primary position and the secondary position. This actuator further includes second rotating means for rotating about the axis. The second rotating means is offset from and fixedly connected to the first rotating means. The second rotating means also extends between the axis and the second connecting means. Further, the second rotating means is configured to rotate about the axis upon the first rotating means rotating about the axis. In addition, the first rotating means and the second rotating means have different lengths. 
     There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of an actuator according to a first embodiment of the present invention. 
         FIG. 2  is a perspective view of the actuator illustrated in  FIG. 1  wherein the housing has been removed and wherein all of the components of the actuator are engaged with each other. 
         FIG. 3  illustrates the actuator illustrated in  FIG. 2  wherein the translating component  18  is in a secondary position. 
         FIG. 4  is an exploded view of a portion of the actuator illustrated in  FIGS. 1-3 . 
     
    
    
     DETAILED DESCRIPTION 
     Certain embodiments of the present invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout.  FIG. 1  is an exploded view of an actuator  10  according a first embodiment of the present invention. The actuator  10  is encased within a housing  12  that surrounds all of the components of the actuator  10  illustrated in  FIG. 1 , except for the user interface  16 , at least part of which typically extends outside of the housing  12 , and the input connection  14 , at least part of which extends outside of the housing  12  in some embodiments of the present invention. 
       FIG. 2  is a perspective view of the actuator  10  illustrated in  FIG. 1  wherein one side of the housing  12  has been removed and wherein all of the components of the actuator  10  are engaged with each other. As illustrated in  FIG. 2 , the actuator  10  includes the input connection  14  that is, as illustrated in  FIG. 1 , connected to the user interface  16 . According to certain embodiments of the present invention, the user interface  16  includes a push button that may be depressed by a user to engage the actuator  10 . However, other user interfaces are also within the scope of the present invention, particularly those user interfaces that allow a user to input force and/or pressure to the input connection  14  of the actuator  10  (e.g., switches). 
     The input connection  14  illustrated in  FIGS. 1 and 2  is illustrated as being in the form of a solid component that extends between the user interface  16  and a translating component  18  that is included in the actuator  10 . The input connection  14  may, for example, take the form of a rod, a cylinder or one or more other objects that extend between the user interface  16  and the translating component  18 . 
     In  FIGS. 1 and 2 , the translating component  18  takes the form of a rack gear having a plurality of teeth  20  and is connected to the input connection  14 . When the user interface  16  is not engaged (e.g., when a user is not depressing the push button), the translating component  18  is in the primary position illustrated in  FIG. 2 . However, when the user interface  16  is engaged, the translating component  18  of the actuator  10  illustrated in  FIG. 2  moves to the secondary position illustrated in  FIG. 3 . The translating component  18  typically translates linearly between the primary position and the secondary position upon the user interface  16  being engaged, but some embodiments of the present invention allow for the translating component  18  to translate non-linearly as well. Further, according to other embodiments of the present invention, the translating component  18  rotates and/or undergoes other kinds of motion beyond pure translation. 
     In addition to the above-discussed component, the actuator  10  illustrated in  FIGS. 1-3  also includes a left-side gear lever  22  and a right-side gear lever  24  positioned on either side of the translating component  18 . The left-side gear lever  22  includes a first arm  26  that functions as a primary lever extending between the translating component  18  and a first axis  28  about which the left-side gear lever  22  rotates. The left-side gear lever  22  also includes a second arm  30  that is offset from and fixedly connected to the first arm  26 . The second arm  30  functions as a secondary lever and extends between the first axis  28  and a first output connection  32 . In turn, the first output connection  32  has a left-side cable  34  removably connected thereto. Although the first arm  26  and second arm  30  illustrated in  FIGS. 1-3  are incorporated within a single gear lever  22 , according to alternate embodiments of the present invention, the two arms  26 ,  30  may be included as individual components within the actuator  10 . 
     As illustrated in  FIGS. 1-3 , the first arm  26  includes a set of lever arm teeth  36  that engage with the above-discussed set of rack gear teeth  20  on the translating component  18 . Although the set of rack gear teeth  20  and the set of lever arm teeth  36  illustrated in  FIGS. 1-3  are all substantially identical in geometry, alternate embodiments of the present invention allow for the teeth on the translating component  18  and left-side gear lever to be of differing geometries. It should also be noted that, although the use of gear teeth in the above-discussed actuator  10  reduces the likelihood of slippage, other embodiments of the present invention can use friction and/or other mechanisms instead of gear teeth for engaging the translating component  18  and the first arm  26 . 
     As the translating component  18  moves/translates between the primary position illustrated in  FIG. 2  and the secondary position illustrated in  FIG. 3 , the first arm  26 , which is engaged with the translating component  18 , rotates about the first axis  28 . Since it is fixedly connected to the first arm  26 , the second arm  30  also rotates about the first axis  28 . 
     The first arm  26  and the second arm  30  may be configured to have substantially equal lengths. However, the first arm  26  and the second arm  30  illustrated in  FIGS. 1-3  have different lengths. According to certain embodiments of the present invention, the length of the second arm  30  is greater that the length of the first arm  26 . According to such embodiments, when the user interface  16  is depressed and causes translation of the translating component  18 , the portion of the first arm  26  furthest from the first axis  28  is moved a first distance about the first axis  28  and the portion of the second arm  30  furthest from the first axis  28  is moved a second distance about the first axis  28  that is greater than the first distance. As such, a relatively small displacement of the translating component  18  can cause the second arm  30  to move a relatively large distance. Also, since the second arm  30  is connected to the left-side cable  34  through the first output connection  32 , the left-side cable  34  is pulled a relatively large distance. When using such an embodiment, the displacement input by a user through the user interface  16  may be magnified and output through the left-side cable  34  or some other component that is connected to the actuator  10 . 
     According to other embodiments of the present invention, the length of the second arm  30  is less than the length of the first arm  26 . According to such embodiments, the portion of the second arm  30  that is furthest from the first axis  28  moves a relatively short distance compared to the distance traveled by the portion of the first arm  26  that is furthest from the first axis  28 . However, by virtue of being shorter than the first arm  26 , the second arm  30  benefits from a mechanical advantage and is therefore capable of exerting a relatively large amount of force on the left-side cable  34 . When using such an embodiment, the force input by a user through the user interface  16  may be magnified and output through the left-side cable  34  or some other component that is connected to the actuator  10 . 
       FIGS. 1-3  also illustrate that the actuator  10  includes a return spring  38  that is adjacent to the translating component  18 . According to certain embodiments of the present invention, the return spring  38  applies little or substantially no force to any portion of the actuator  10  while the translating component  18  is in the primary position illustrated in  FIG. 2 . However, when the translating component  18  is the secondary position illustrated in  FIG. 3 , the return spring  38  biases the translating component  18  to the primary position. According to these embodiments, the return spring  38  thereby assures that, once the user interface  16  is released after being engaged by a user, the user interface  16  return to its initial position. Thus, when the user interface  16  is a push button, once a user stops depressing the push button, the button “pops-up” or returns to its original position. 
       FIG. 4  is an exploded view of a portion of the actuator  10  illustrated in  FIGS. 1-3 . As illustrated in  FIG. 4 , the left-side gear lever  22  and the right-side gear lever  24  are both attached to the housing  12  using retaining caps  40 . However, alternate methods of connecting the gear levers  22 ,  24  to one or more of the other components of the actuator  10  are also within the scope of the present invention. For example, rivets, bolts and/or pins may be used. 
     Also illustrated in  FIG. 4  are two torsional springs  42 , one of which is positioned adjacent to each of the gear levers  22 ,  24  discussed above. In the actuator  10  illustrated in  FIG. 4 , when either of the gear levers  22  rotates from a primary lever position (illustrated in  FIG. 2 ) to a secondary lever position (illustrated in  FIG. 3 ) as a result of the translating component  18  translating between the primary and secondary positions above, at least one of the torsional springs  42  gets compressed and begins biasing the respective gear lever  22 ,  24  to the primary lever position. In other words, at least one torsional spring  42  biases at least one of the gear levers  22 ,  24  toward the position that the gear lever  22 ,  24  was in when the translating component  18  was in the primary position. Since each gear lever  22 ,  24  is connected with the user interface  16  through the translating component  18  and input connection  14 , each of the torsional springs  42 , like the return spring  38 , ensures that the user interface  16  returns to an initial position when the user interface  16  is no longer being depressed or otherwise engaged by a user. 
     As illustrated in  FIG. 2 , the actuator  10  also includes an auxiliary connection  44  that may be connected to one or more of the components included in the actuator  10 . According to certain embodiments of the present invention, the auxiliary connection  44  is configured to be connected to an auxiliary input (not shown) that may be used to engage the actuator  10  in a manner alternate to using the user interface  16 . For example, the auxiliary connection  44  may be connected to an auxiliary input (e.g., a handle or latch) that, when pulled (i.e., engaged), pulls the auxiliary connection  44  downward. The auxiliary connection  44 , in turn, pulls the translating component  18  into the secondary position discussed above. 
     According to certain embodiments of the present invention, the auxiliary connection  44  is connected to a trunk release mechanism. According to such embodiments, the actuator  10  is used to effectuate the opening and closing of the trunk of an automobile. If a person were to get stuck within the trunk and were therefore unable to engage the user interface  16  on the outside of the automobile, the person would still be able to engage the trunk release mechanism (e.g., a trunk release handle on the inside of the trunk). The trunk release mechanism would apply a force to (e.g., pull) the auxiliary connection  44  and thereby engage the actuator  10  and open the trunk. 
     Although the first output connection  32  illustrated in  FIG. 2  is connected to a cable, other types of components may be engaged with the actuator  10 . For example, rods or cylinders may be engaged with the actuator  10 . 
     Although only the left-side gear lever  22  has been discussed in detail above, one of skill in the art will appreciate that the right-side gear lever  24  is substantially identical to the left-side gear lever  22  and therefore acts in a similar and complementary manner in the actuator  10 . According to alternate embodiments of the present invention, the left-side gear lever  22  and the right-side gear lever  24  are substantially mirror images of each other and also act in a similar and complementary manner. According to still other embodiments of the present invention, the geometries of the left-side gear lever  22  and of the right-side gear lever  24  are different (e.g., the arms are of different lengths and/or are positioned at different angles relative to each other). 
     The right-side gear lever  24  includes a second output connection  46  that is engaged with a right-side cable  48 . The right-side gear lever  24  also includes a third arm  50  that extends between the translating component  18  and a second axis  52 . The right-side gear lever  24  is configured to rotate about the second axis  52  upon the translating component  18  translating between the above-discussed primary and secondary positions. The right-side gear lever  24  also includes a fourth arm  54  that is offset from and fixedly connected to the third arm  50 . According to alternate embodiments of the present invention, the third arm  50  and fourth are  54  are individual components and not part of the same gear lever  24 . 
     The fourth arm  54  extends between the second axis  52  and the second output connection  46 . The fourth arm  54  is configured to rotate about the second axis  52  upon the third arm  50  rotating about the second axis  52  pursuant to the translating component  18  translating between the primary and secondary positions. Like the first arm  26  and second arm  30  discussed earlier, the third arm  50  and fourth arm  54  are typically of different lengths. 
     Upon practicing the present invention, one of skill in the art will appreciate that the lengths and relative lengths of the first arm  26 , second arm  30 , third arm  50  and/or fourth arm  54  are application-specific and may be selected so as to be appropriate for achieving one or more particular purposes. For example, when a greater output of force is desired on the left side of the actuator  10  illustrated in  FIG. 2 , the length of the second arm  30  may be shortened relative to the length of the first arm  26 . 
     According to certain embodiments of the present invention, the length of the first arm  26  relative to the length of the second arm  30  differs from the length of the third arm  50  relative to the length of the fourth arm  54 . In such embodiments, each of the cables  34 ,  48  is subjected to a different amount of force and/or displacement. However, according to other embodiments of the present invention, the length of the first arm  26  relative to the length of the second arm  30  is substantially equal to the length of the third arm  50  relative to the length of the fourth arm  54  and the cables  34 ,  48  are subjected to substantially equal amounts of force and displacement. 
     In the actuator  10  illustrated in  FIGS. 1-4 , the left-side cable  34  and the right-side cable  48 , along with their respective output connections  32 ,  46 , are positioned substantially opposite to each other. However, according to alternate embodiments of the present invention, instead of being offset by substantially 180° degrees, the two cable  34 ,  38  illustrated in  FIGS. 1-4  may be offset at alternate angles. In addition, one of skill in the art will appreciate that, by adding additional gear levers around the translating component  18  and by including rack gear teeth  20  that extend around the translating component  18 , more that two cables may be connected to the actuator  10 . 
     The above-discussed actuator  10  includes a first arm  26  and a third arm  50  that have substantially equal lengths. Likewise, the second arm  30  and the fourth arm  54  included in the actuator  10  also have substantially equal lengths relative to each other. While this promotes symmetry and reduces the amount of torsion on the overall actuator  10 , arms included in alternate embodiments of the actuator  10  may have alternate lengths. 
     According to yet another embodiment of the present invention, a method of actuating a system is also provided. The method includes engaging a user interface. This engaging step may be implemented, for example, by depressing a push button that functions as the user interface. 
     The method also includes translating a first component between a primary position and a secondary position upon the user interface being engaged. If using the actuator  10  discussed above, this translating step may be implemented by moving the translating component  18  between the above-discussed primary and secondary positions. 
     The method also includes rotating a primary lever about a first axis upon the translating component translating between the primary position and the secondary position. According to certain embodiments of the present invention, when implementing this step, the primary lever is chosen to extend between the translating component and the first axis. This first rotating step may be implemented for example, by rotating the first arm  26  of the left-side gear lever  22  discussed above. 
     The method also includes rotating a secondary lever about the first axis upon the primary lever rotating about the first axis. When implementing this step, the secondary lever is typically chosen to extend between the first axis and a first output connection. Also, the second lever is typically chosen to have a different length than the primary lever and is commonly chosen to be offset from and fixedly connected to the primary lever. This step may be implemented, for example, by rotating the second arm  30  in the actuator  10 , as discussed previously. 
     The method further includes rotating a tertiary lever about a second axis upon the translating component translating between the primary position and the secondary position. When implementing this step, the tertiary lever is typically chosen to extend between the translating component and the second axis. The method also includes rotating a quaternary lever about the second axis upon the tertiary lever rotating about the second axis. When implementing this step, the quaternary lever is commonly chosen to be offset from and fixedly connected to the tertiary lever. Also, the quaternary lever is typically chosen to extend between the second axis and the second output connection. Also, the tertiary lever and the quaternary lever usually are chosen to have different lengths. 
     According to certain embodiments of the present invention, the method also includes pulling a first cable with the first output connection upon the secondary lever rotating. The method further includes pulling a second cable with the second output connection upon quaternary rotating. When implementing such embodiments, the first cable and the second cable are often positioned substantially opposite each other. However, according to other embodiments of the present invention, one, two or more cables may be pulled or pushed (if the  26 ,  30 ,  50 ,  54  are positioned accordingly). According to these embodiments, the plurality of cables (or other components such as, for example, cylinders and rods) may be offset from each other by almost any angle. 
     When implementing the above-discussed embodiments of the method, the primary lever and the tertiary lever are typically chosen to have substantially equal lengths. However, no particular restrictions are placed on the lengths or relative lengths of any of the levers or arms in actuators according to the present invention. 
     The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.