This invention relates to mechanisms for changing a texture or contour of a surface and more particularly relates to mechanisms configured move at least a portion thereof from a position in a plane to a position extending out of the plane.
There are many mechanisms that provide changeable contours on a surface. For example, spring biased buttons on an electronic control device, or keys on a keyboard are capable of being depressed and released. Other buttons have stable positions and remain depressed once moved. These buttons are supported and moved by a variety of mechanical elements, including rigid joint elements forming linkages. For the particular case of an element of a mechanism moving from within a plane to a location outside the plane, J. J. Parise describes ortho-planar mechanisms. (See Parise, J. J., Howell, L. L., and Magleby, S. P., 2000. “ORTHO-PLANAR MECHANISMS.” In Proceedings of the 2000 ASME Design Engineering Technical Conferences.)
Most springs are compliant elements that can be collapsed under force and return to their original position when released. These springs are typically one-piece, and are usually disposed in abutment with a base element on one end and an element to be biased on the other end.
Linkages and other mechanisms for changing configurations and/or applying a force by actuation are well known for most mechanical design regimes. An example of a micro level device that has a configuration-changing mechanism is described by C. P. Lusk in his 2005 PhD dissertation. (See Lusk, C. P., 2005. “ORTHO-PLANAR MECHANISMS FOR MICROELECROMECHANICAL SYSTEMS.” PhD Dissertation, Brigham Young University, Provo.) Lusk's device is an ortho-planar mechanism for microelectromechanical systems.
Compliant system design and analysis has been addressed by L. L. Howell. (See Howell, L. L., 2001. “COMPLIANT MECHANISMS.” John Wiley & Sons, New York.)
An area of deficiency is highlighted by the fact that many input devices have arrays of push buttons for user input that are too complicated or are otherwise inadequate and/or awkward to use. For example, as electronics have become smaller and more complex, their input devices must be fit into smaller footprints or must utilize alternate functions for the same buttons such as through an “Alt” key.
The known mechanisms forming these input devices have not adequately addressed needs for greater compactness, cost savings, ease of manufacture, and more sophisticated results through manipulation of elements of input devices for the purpose of adjusting a configuration of the input device.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that has a low profile, is light weight, costs little to manufacture, and is capable of being reconfigured into a desired configuration. Beneficially, such an apparatus, system, and method would enable plural arrays of positions on a surface or plane to be independently or dependently moved. Accordingly, the present invention overcomes many or all of the above-discussed shortcomings in the art.
In a simple form, a mechanism in accordance with embodiments of the present invention is capable of being transformed from a planar to a non-planar configuration. The mechanism includes a first layer and a second layer. The mechanism also includes at least one linkage interconnecting the first and second layers. The layers are flat and generally define a plane in a first of two stable positions. A portion of at least one of the layers projects out of the plane in the second of the two stable positions.
The layers may be compliant, and the linkage may include a portion of at least one of the first and second layers. The linkage may be a first linkage of a plurality of linkages that interconnect the first and second layers. In one embodiment, the mechanism is a spherical mechanism. The mechanism may include at least one bi-stable biasing mechanism for biasing the second layer into each of the two stable positions relative to the first layer.
In another simple form, embodiments of the invention include an apparatus for changing a position or contour of a surface. The apparatus includes at least one configuration changing mechanism having first and second layers coupled together and movable relative to each other. In one embodiment, a cover is supported on the at least one mechanism. A surface on the cover has a first position on the cover that is adjustable to a second position by moving the at least one mechanism from a first configuration to a second configuration.
The apparatus may include a plurality of similar mechanisms. The apparatus may also include at least one actuator that is coupled to the configuration changing mechanism or mechanisms. The actuator may be configured to move the first and second layers of the mechanism(s) between first and second positions. In embodiments having a plurality of configuration changing mechanisms, the apparatus may include a plurality of actuators. The actuators may be coupled to respective distinct sets of the configuration changing mechanisms among the plurality of configuration changing mechanisms for selectively moving the distinct sets of configuration changing mechanisms. The plurality of actuators may be independently coupled to the configuration changing mechanisms and configured to independently actuate the respective sets of configuration changing mechanisms. Alternatively, the actuators may be coupled in a dependent manner such that actuation of one set may preclude actuation of another set, or actuation of a set may cause actuation of another set.
In still another simple form, a system in accordance with embodiments of the invention includes a configuration-adjusting mechanism. The system includes a base layer and an actuation layer movably coupled to the base layer. At least one linkage is coupled to each of the base layer and the actuation layer. An actuator is coupled to the actuation layer for moving the actuation layer between first and second positions. The base layer, actuation layer, and at least one linkage form an ortho-planar configuration-adjusting mechanism.
The actuation layer may be rotatably coupled to the base layer. Two or more of the base layer, the actuation layer, and the at least one linkage may form a spherical mechanism. One or more of the base layer, actuation layer, and linkage may form a compliant mechanism. The first and second positions may be stable positions. The system may further include a biasing mechanism in which the biasing mechanism, base layer, actuation layer, and one or more linkage form a bi-stable mechanism for moving the actuation layer between the first and second positions.
The system may further include an electronic device or control panel. The electronic device or control panel may include a housing. The ortho-planar configuration-adjusting mechanism may be supported on the housing.
The system may further include a plurality of linkages. The plurality of linkages may be configured to extend transversely from a plane of the ortho-planar configuration-adjusting mechanism. Thus, the plurality of linkages may correspond to an array of positions in the plane or on a surface of the housing.
In one embodiment, the plurality of linkages may include at least a first set of the linkages in the array of positions and a second set of linkages in the array of positions. The first and second sets of linkages may be operatively connected to the actuator(s) for independent actuation of the first and second sets of the linkages in the array of positions. Alternatively or additionally, the plurality of linkages include at least one set of linkages in the array of positions dependently coupled to another set of linkages in the array of positions for dependent actuation or movement of the sets of the linkages in the array of positions.
In another embodiment, the array of positions comprises a plurality of patterns. The system may further include a first set of linkages corresponding to one of the patterns and a second set of linkages corresponding to another of the patterns.
In still another simple form in accordance with embodiments of the invention, a method for changing a configuration includes forming a linkage from at least two layers of sheet material. The method also includes causing the linkage to move from a plane generally corresponding to the layers to a position extending transverse to the plane. The operation of causing includes one or more of mechanically and electrically actuating the linkage to move at least a portion of one of the layers relative to the other of the layers.
The method may include biasing the portion of the one of the layers into the position extending transverse to the plane. The position extending transverse to the plane may be a first stable position. The portion may have a second stable position corresponding to the portion being in the plane. The method may also include selectively moving the portion between the first and second stable positions.
The method may further include causing a plurality of linkages to move from the plane to a position extending transverse to the plane in which the plurality of linkages corresponds to an array of positions in the plane. The operation of causing the plurality of linkages to move may include moving at least one set of the linkages in the array of positions independently of another set of the linkages in the array of positions. Alternatively or additionally, the operation of causing a plurality of linkages to move may include moving at least one set of linkages in the array of positions dependent on actuation or movement of another set of the linkages in the array.
In one embodiment, the array of positions may include a plurality of patterns. The method may thus further include selectively causing a first set of linkages corresponding to one of the patterns to move and a second set of linkages corresponding to another of the patterns to move.
Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
Furthermore, the described features, advantages, and characteristics of the invention may be combined in any manner in one or more embodiments. It is to be understood that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. Additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
More particular descriptions of examples of the embodiments briefly described above are set forth with reference to the appended drawings. These drawings depict examples and are not to be considered to be limiting of its scope.
Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of user selections, etc., to provide a thorough understanding of embodiments of the invention. However, the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
The schematic flow chart diagrams included herein are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.
Several terms are used in this specification that have definitions that are known in the art. However, several definitions are set forth here for clarity. The term “compliant” as used herein in reference to mechanisms or portions of mechanisms refers to mechanisms that gain some or all of their motion through the deflection of flexible members. The term “ortho-planar” refers to mechanisms in which all the links can be located in a single plane and having motion out of the plane. The term bi-stable refers to mechanisms whose total potential energy curves have two minima. That is, bi-stable mechanisms have two stable equilibrium configurations or states. The term “planar” as it refers to “mechanisms” refers to mechanisms that have joint axes that always remain parallel. At the same time, the bars of a straight-barred linkage of a planar mechanism remain in the same general plane. The term “spherical”, as it refers to a mechanism, refers to a mechanism with joint axes all intersecting at a single point. Thus, the links of a spherical mechanism travel along a spherical surface centered at the joint axis intersection.
Embodiments of the present invention may include principles of lamina emergent mechanisms (LEMs). LEMs are mechanical devices that are fabricated from a planar material (a lamina) and that have motion that emerges out of the fabrication plane. LEMs achieve their motion from the deflection of flexible members. Thus, LEMs are compliant mechanisms. They are also monolithic. LEMs have the potential to perform sophisticated mechanical tasks with simple topology. Furthermore, the ability to fabricate LEMs from planar layers of material makes it possible to manufacture them by using simplified sheet material processes. Hence, high-performance, compact devices can be fabricated at low manufacturing cost. On the other hand, LEMs present challenging design issues, some of which are beginning to be addressed though innovative activities including those associated with the embodiments of the present invention.
As stated,
The mechanism can be formed to create two layers 15, 18 of flexible sheet material, though a third layer of thin flexible material may be added on top for aesthetic purposes, as will be describe with reference to
As shown, three bifurcated linkages 25, 26, 27 move from a flat configuration shown in
As shown, the upper layer has ring tabs 35, 36, 37 that are integral with and extend radially inwardly. The ring tabs 35, 36, 37 are integrally connected by living hinges 30a, 31a, and 32a to the linkages 25, 26, 27, respectively. The ring tabs 35, 36, 37 also form part of the linkages 25, 26, 27, respectively. Similarly, lower layer 18 has actuation layer ring tabs (shown in
In one embodiment, the mechanism 12 uses three spherical slider-crank mechanisms formed by linkages 25, 26, 27 which are coupled so that a single input through a lever 72 actuates all three mechanisms or linkages 25, 26, 27 simultaneously. When the mechanism 12 is actuated by a rotational input, the linkages 25, 26, 27, or portions thereof, move out of the plane to increase the height of the mechanism 12. A height of a local surface (shown in
As shown in
In the illustrated embodiment, this mechanism 12 is fully-compliant, and uses very thin flexures in the form of living hinges between relatively stiff members to achieve a predetermined motion. As shown in
It is to be understood that the configuration-adjusting mechanism 12 may be designed and configured to fit any of a variety of applications. The mechanism specifications may be changed to suit a particular application. This customization is not trivial because the design requirements and analysis, including modeling are at a higher, more challenging level than those mechanisms that can be modeled with linear methods or FEA. This is, in part due to the rigors of designing mechanisms capable of forming sophisticated or complex contours of textures from sheet material. While the linkages have been shown and described as being monolithic and/or compliant, it is to be understood that in some applications and embodiments, all or part of the mechanism 12 may be replaced by non-compliant elements such as rigid element joints at hinge points.
In creating the configuration-adjusting mechanism 12 for a particular application, it is important to know key output parameters, such as total height required, total actuation torque, total lifting force, and maximum size. Creating a mechanism 12 tailored to these needs calls for selection of a geometry and/or materials in order to get the correct overall torque characteristics with the correctly sized mechanism 12. Possible geometry changes include the length, width, and height of the linkages 25, 26, 27, the resilient members 66, 67, 68, 69 of the bi-stable mechanism 54, and the flexibility of the living hinges between portions of the linkages 25, 26, 27, 28. When a particular combination does not meet particular criteria, alternative materials may be selected or other factors adjusted for achieving the proper strength and stiffness characteristics.
One reason for changing geometry and/or materials is for the purpose of scaling a size, strength, and/or stiffness up or down while still retaining bi-stable characteristics. Scaling may be implemented to preserve other characteristics or may be done while maintaining desired characteristics. By way of example, retaining the bi-stable characteristic while scaling up or down can be achieved by calculating the torque rotation curves for both the linkages 25, 26, 27 and the rotationally stable bi-stable biasing mechanism 12, and adding them together. If the resulting curve for the total torque input moves below zero, the configuration adjusting mechanism will tend to stay at the point where the torque is lowest, which is a stable equilibrium point, and which occurs once the resilient members have moved past their bent or compressed condition and have straightened out to their relaxed state. In this configuration, there is no potential energy. The mechanism 12 of the embodiments of
Many tools may be utilized in designing a particular mechanism in accordance with embodiments of the present invention. However, these tools have their limitations when confronting the complexities of the required designs. For example, compliant mechanisms require nonlinear analysis. Therefore, traditional techniques employing linear beam theory and linear finite element analysis (FEA) cannot accurately model the large motions incident to many compliant mechanisms. Furthermore, nonlinear FEA is too cumbersome to be useful in the initial stages of compliant mechanism design. Rather pseudo-rigid-body model (PRBM) has been developed for designing and analyzing compliant mechanisms. The PRBM models flexible members as rigid links connected by pin joints and torsional springs. This allows greatly simplified models suitable for use with traditional kinematics analysis techniques. The PRBM can be used extensively in the initial design stages, and combined with nonlinear FEA in later stages. (See Howell, L. L., 2001. “COMPLIANT MECHANISMS.” John Wiley & Sons, New York.) For the case of spherical slider-crank linkages, spherical kinematics is considered to be more general than planar kinematics. Spherical mechanisms are much less common and more complicated to design than planar mechanisms. However, they offer unique opportunities for design. In this regard, closed form equations can be derived for spherical configurations using spherical trigonometry. (See Lusk, C. P., 2005. “ORTHO-PLANAR MECHANISMS FOR MICROELECROMECHANICAL SYSTEMS.” PhD Dissertation, Brigham Young University, Provo.) The advantage of utilizing these closed form equations is that doing so provides a very clean approach to design and analysis of spherical configuration-adjusting mechanisms and enables design of mechanisms having complex motions in very compact footprints.
Another application includes a reconfigurable user interface for input devices like the control panel 110 of
Systems in accordance with embodiments of the present invention may include housings for the various control panels including remote controls, cell phones, and other devices, which may include a wide variety of structures and elements. However, it is to be understood that a mounting surface for the configuration-adjusting mechanisms may be located at any position on the housing including on an inside, back, or front. The configuration-adjusting mechanisms may be positioned to cause portions thereof to extend out of the plane.
While, the configuration-adjusting mechanisms have been described as being formed of two or more layers of a sheet material, it is to be understood that similar mechanisms maybe created from a single layer which, through its compliant characteristics, is made to function like the mechanisms described herein. One way to achieve this is through injection molding or similar processes. In any case, the mechanisms may be monolithic or one-piece. Alternatively, the mechanisms may be made to be monolithic by coupling the layers and portions thereof so that all the elements of the mechanism are integrally connected and the only relative movement between elements is due to the compliant nature of the layer(s).
While the contour adjustment has been described in terms of configuration adjustment, alternative expressions for the adjustments or changes that are caused by the mechanisms of the present invention may include mechanisms for texturing, or mechanisms for changing a surface texture of a device. An array of positions for the configuration-adjusting mechanisms or arrays of mechanisms corresponding to predetermined patterns of emergent buttons to be actuated enable changing the texture or contour of a device.
The term mechanism is used herein as referring primarily to the configuration-adjusting mechanism. However, one definition of a mechanism is a device that transfers, translates, or imparts movement. In this sense the elements referred to primarily as linkages are also mechanisms. Thus, the term mechanism is to be taken in the context of the particular portion of the disclosure, and in the context of the disclosure as a whole. The term linkage is to be taken to include linkages with rigid elements at the joints as well as compliant mechanisms that impart forces and motion in a manner constrained by the specific structure and characteristics of the material providing the compliant mechanisms. Thus, it is to be understood that the coupling of the tabs described herein to each of two layers enables forces and motion to be transferred through a compliant material interconnecting the tabs. The interconnecting material may be in and form part of at least one of the layers such that the coupling of the tabs forms a linkage out of at least portions of two layers of a sheet material.
The number and variety of applications in which embodiments of the present invention may be applied is unlimited. Example categories include those described above, aerospace components, and medical implants. In particular, embodiments of the present invention could be applied to devices that are compact during transport and then deployed when at the location of operation. This may include surgical devices, mechanisms intended for use in space, and components for search and rescue operations. The embodiments may also help meet a need for compact packaging and shipping, such as for high-volume packaging that reduces costs associated with handling, storing, and shipping products. The embodiments of the present invention may be applied in situations with limited manufacturing processes available. For example, the embodiments may be applied to microelectromechanical systems (MEMS) and other applications that are cost-sensitive.
One of the advantages of forming the mechanisms of the embodiments described herein as LEMs is that LEMs are manufactured in a plane having a flat initial state. Another advantage is that LEMs are monolithic, or can be made monolithic. Furthermore, LEMs lend themselves to interaction of a plurality of LEMs.
Since the embodiments of the mechanisms of the present invention can be fabricated from a single planar layer of sheet material, simplified processes can be used to manufacture the mechanisms. The ability to utilize sheet material provides the opportunity to use any of a large variety materials including sheet plastic and sheet metal, which are available in high-quality at low cost. At the micro level, advantages of single-layer MEMS fabrications include the inherent cost savings and reliability advantages. At the macro level, the layers maybe cut or otherwise processed by stamping, fine blanking, laser cutting, water jet cutting, plasma cutting, and/or plasma cutting, and wire electrical discharge machining (EDM). In any case, layers of sheet material can be used to create mechanisms capable of sophisticated motions and complex tasks including movement from a flat or non-deployed condition into distinct configurations such as to form distinct contours. It is to be understood that in some embodiments, the non-deployed condition may be a non-flat configuration. Nevertheless, the mechanisms may be monolithic or made to be monolithic.
Although the mechanisms and their linkages in accordance with embodiments of the present invention could be made with rigid coupling elements or rigid pin joint linkages, one-piece or monolithic and compliant linkages have certain advantages. For example, backlash and wear associated with typical pin joints can be avoided by incorporating monolithic, compliant mechanisms instead. Also, the monolithic, compliant mechanisms are lighter in weight and reduce or eliminate friction. Furthermore, an amount of assembly can be reduced by forming the mechanisms of monolithic, compliant linkages, which may form part of one or both of the layers.
Many materials may be used to form the layers in the embodiments of the present invention. For example, polypropylene was used for the prototypes upon which the embodiments of
It is to be understood that the term linkage, as used herein, is not to be limited to any particular linking mechanism. For example, even though linkages are sometimes considered to include rigid elements in the joints, the term “linkage” as used herein includes compliant coupling mechanisms in which the flexibility of all or part of the linking elements allows articulation, force transfer, and other linkage functions that are important for movably coupling at least two elements together.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application claims priority to U.S. Provisional Patent Application No. 60/959,422 entitled “OUT-OF-PLANE MORPHING MECHANISM” and filed on Jul. 14, 2008 for Larry L. Howell et al., which is incorporated herein by reference.
Number | Date | Country | |
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60959422 | Jul 2007 | US |