Abstract:
The present invention includes a knob assembly which provides rotational movement and translational travel along an axis of dual and independent rotary knobs. The present invention controls electronics within a housing, without requiring protrusion into the housing. Having no protrusions into the housing avoids exposure of the electronics within the housing to environmental contaminants or electromagnetic interference. The components of the dual independent push button rotary knob assembly may operate without need for O-rings, gaskets, or any other applied sealants to prevent containments from entering the housing. Assembly of the knob assembly is simplified, because the rotary knob assembly may be installed and replaced without any tools and without need to access the interior of the housing. Furthermore, if any part of the assembly is damaged, the rotary knob assembly, in part or whole, may be replaced without compromising any seal provided to the exterior surfaces of the housing.

Description:
RELATED APPLICATIONS 
       [0001]    The present application is a Continuation-In-Part of U.S. patent application Ser. No. 12/246,743 filed Oct. 7, 2008, which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates, in general, to a knob assembly. More specifically, the present invention relates to a dual independent push button rotary knob assembly which provides contactless control of an electronic device residing in a housing, without direct physical contact with the interior of the housing. 
       BACKGROUND OF THE INVENTION 
       [0003]    In many electronic housings, in which space is at a premium, control functions are often consolidated in a single control knob. For example, a rotary knob which has several rotational positions for activating several electronic functions may be combined with a push button switch, which may have only one function for turning the electronics on/of functions. While enabling multiple control functions of the electronics in the housing, the conventional rotary-push button control complicates the assembly of the housing and makes replacement of the control knob difficult. Additionally, the complex housing needed for conventional rotary-push button controls prevents the use of more complex, multi-functional rotary-push buttons knobs. 
         [0004]    A conventional control knob assembly typically requires protrusion into the housing of the electronics, in order to transmit the various controls to the electronics. The protrusion creates an opening into the housing which may allow environmental contamination and electromagnetic interference (EMI) into the electronics. 
         [0005]    To mitigate the risks associated with environmental contamination and EMI, operator control knobs of this type have utilized O-rings, gaskets, or other applied sealants. This, in turn, may be messy and may further complicate the assembly or maintenance of the control knob. Furthermore, because the control knob requires a protruding member to be inserted into the housing, the protruding member occupies a portion of the internal volume of the housing which may be better used for other purposes. 
         [0006]    As will be explained, the present invention provides a rotary knob assembly that has advantages over conventional rotary knob assemblies, because the rotary knob assembly of the present invention does not require any intrusion into the housing, nor direct contact with the internal electronics of the housing. As will be described, the present invention provides a push button and dual rotary knob assembly which contactlessly controls an electronic device, without protrusion into the housing of the electronics and without direct contact with the electronics. 
       SUMMARY OF THE INVENTION 
       [0007]    To meet this and other needs, and in view of its purposes, the present invention provides a knob assembly including two encoders disposed internally within a housing and dual independent push button rotary knobs, containing two magnets, disposed externally to the housing. An interface plate of the housing is interposed between the encoders and the knob assembly and physically isolates the interior of the housing from the dual independent rotary knobs. The interface plate prevents environmental leakage and electromagnetic interference from entering the housing. 
         [0008]    The encoders are configured to decode the angular rotation of an inner and an outer rotary knob and transmit corresponding control functions to the electronics within the housing. An encoder corresponding with the magnet within an inner rotary knob having push button functionality is configured to decode and transmit the axial translational to the electronics within the housing as a further control function. 
         [0009]    Another embodiment of the present invention provides a control unit including a knob assembly. The knob assembly includes two encoders disposed internally within a housing and a knob assembly, containing two magnets, disposed externally to the housing. An inner rotary knob functions as both a rotary knob, providing rotational movement, and as a push button, providing axial translation. An outer rotary knob provides independent rotational movement from the inner rotary knob. The push button may be depressed independently of any rotational movement to either of the rotary knobs. A boundary surface of the housing is interposed between the encoders and the knob assembly and physically isolates the interior of the housing from the dual independent push button rotary knob assembly. The boundary surface prevents environmental leakage and electromagnetic interference from entering the housing. The encoders are configured to decode the angular orientation of the two rotary knobs and the axial translation of the inner push button rotary knob. 
         [0010]    Furthermore, the present invention includes a method of controlling an electronic device disposed within a housing. The electronic device may be controlled by the steps of: (a) depressing an inner push button rotary knob disposed externally to the housing, (b) axially rotating the inner rotary knob, (c) contactlessly communicating the translational and rotational positions of the inner rotary knob to a first encoder, disposed internally within the housing, without any physical contact between the inner rotary knob and the first encoder, and (d) decoding, by the first encoder, the translational and rotational position of the inner rotary knob and activating independently at least one control function of the electronic device. The method may further include the steps of (e) axially rotating an outer rotary knob, (f) contactlessly communicating rotational position of the outer rotary knob to a second encoder, disposed internally within the housing, without any physical contact between the outer rotary knob and the second encoder, (g) decoding, by the second encoder, the rotational position of the outer rotary knob; and (h) activating a further independent control function of the electronic device. 
         [0011]    It is understood that the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention is best understood from the following detailed description when read in connection with the accompanying drawings. Included in the drawings are the following figures: 
           [0013]      FIG. 1  is a perspective view of the snap-on, push button, dual independent rotary knob assembly in accordance with an embodiment of the present invention; 
           [0014]      FIG. 2  shows a cross-section of the rotary knob assembly shown in  FIG. 1 ; 
           [0015]      FIG. 3  is an exploded cross-sectional view of the rotary knob assembly shown in  FIG. 2 ; 
           [0016]      FIG. 4  is an exploded perspective view of the rotary knob assembly of  FIG. 1 ; 
           [0017]      FIG. 5  is a conceptual view of an embodiment of the present invention, including two encoders operating with the inner rotary knob magnet and the outer rotary knob magnet ring shown in  FIG. 4 ; 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The present invention includes a push button dual-independent rotary knob assembly. As will be explained, the knob assembly provides rotational movement and translational travel along an axis. Unlike conventional knobs and switches, the present invention controls electronics within a housing, without requiring protrusion into the housing. Also unlike conventional knobs and switches, the present invention enables contactless multi-function control through the use of two independent rotary knobs. The components of the present invention may operate without need for O-rings, gaskets, or any other applied sealants between the knob assembly and the housing. 
         [0019]    The push button rotary knob assembly of the present invention offers many advantages, because no portion of the rotary knob protrudes through the housing. For example, (1) there is no leakage path into the housing where environmental contamination or electromagnetic interference (EMI) may enter; (2) the internal volume of the housing, which is dedicated as an interface to the rotary knob, is much smaller than the internal volume required by a conventional rotary knob with the same control functions; (3) a large boss on the housing may be used to guide the rotation of the rotary knob, because the boss does not have to intrude into the housing; and (4) no messy sealants or adhesives are necessary to seal the rotary knob and any housing interface to the rotary knob. 
         [0020]    In addition, conventional knobs and switches require multiple steps and tools to assemble the components of the switch assembly. The push button rotary knob assembly of the present invention, on the other hand, simplifies the assembly process. For example, (1) the rotary knob may be assembled and replaced without any tools; and (2) the rotary knob may be assembled and replaced without need to access the interior of the housing, thereby avoiding exposure of the internal components of the housing to contaminants or the external atmosphere. Additionally, should the rotary knob be damaged, the housing seal is not compromised. Furthermore, the push button rotary knob assembly of the present invention provides dual, independent rotary knobs which enable additional contactless functionality for a user. These and other benefits may be understood by referring to the following description together with the figures. 
         [0021]    Referring first to  FIG. 1 , there is shown an embodiment of the present invention of a push button rotary knob assembly, generally designated as  10 . Shown in  FIG. 1  is the inner rotary knob  16 , the outer rotary knob  12 , a dust shield  30  and an interface plate  24  to which the rotary knob assembly may be attached. Referring next to  FIGS. 2 ,  3  and  4 , the invention includes a cylindrical projection extending externally from interface plate  24  of housing  25  defining a boss  24   b . Outer rotary knob  12  interfaces with boss  24   b  of housing  25 ; and inner push button rotary knob  16  interfaces a cavity  24   e  of boss  24   b . A first magnet  22  is inserted into a central bore in push button knob  16 , at the bottom end of the push button knob adjacent to the cavity bottom  24   c  of interface plate  24 . A second magnet, which may be a magnetic strip  18 , is inserted into a slot in outer rotary knob  12  adjacent to external boundary surface  24   f  of housing  25 . Magnetic strip  18  may be a multi-pole ring magnet and, for example, may include 44 poles. 
         [0022]    The rotational and translational positions of magnet  22  are read by a first encoder  51 , disposed within housing  25  (shown in  FIG. 5 ). As will be described, magnet  22  and encoder  51 , together serving as a first control unit, communicate through cavity bottom  24   c , thereby providing user control of the various modes and functions for operating the electronics  52  within housing  25 . 
         [0023]    The outer rotary knob  12  and magnetic strip  18  rotate together as an assembly. As the knob and magnet assembly are rotated, the magnetic strip  18  is rotated over encoder  50 . Each magnetic pole reversal is sensed by encoder  50  which then provides the relative rotational position of the outer rotary knob  12  to the electronics  52  within housing  25  (shown in  FIG. 5 ). As will be described further, magnetic strip  18  and encoder  50 , functioning together as a second control unit, communicate through external boundary surface  24   f  thereby providing user control of the various modes and functions for operating the electronics  52  within housing  25 . 
         [0024]    A snap dome  20  (see  FIGS. 2 and 3 ) resides between push button  16  and cavity bottom  24   c . The snap dome  20  is positioned with its central portion curved away from interface plate  24  of housing  25  in order to bias the inner push button rotary knob  16  away from cavity bottom  24   c . The O-rings  28  seal the rotary knob assembly and keep particulates from building up within the interior of rotary knob assembly  10 . A dust shield  30  is inserted between outer rotary knob  12  and inner rotary knob  16  to prevent particulate contamination and to center inner rotary knob  16  centered outer rotary knob  12  (see  FIGS. 2 and 4 ). 
         [0025]    The outer rotary knob  12  engages housing  25  at boss  24   b , as shown in  FIG. 2 , without intruding into the interior of housing  25 . The outer rotary knob  12  includes snap retention features  12   b  ( FIG. 3 ). The boss  24   b  may be machined to provide a circumferential slot  24   d  to receive and engage retention features  12   b . The snap retention features  12   b  circumferentially surround the outer face of boss  24   b  and effectively hold outer rotary knob  12  to housing  25 . This manner of attachment allows for easy assembly and replacement, and eliminates any need for intrusion or opening into the interior of the housing. 
         [0026]    The inner rotary knob  16  is received and seated within cavity  24   e  of boss  24   b . The inner rotary knob  16  is captured by boss  24   b  using lip  16   b  which surrounds the base of inner rotary knob  16 . Retaining ring  26  and o-ring  28  also aid in the capture of inner rotary knob  16 . This arrangement captures the inner rotary knob while effectively decoupling any torque between the inner and outer rotary knobs when any of the rotary knobs is rotated. The o-ring  28  and the retaining ring  26  also prevent inadvertent rotation between the rotary knobs. 
         [0027]    In operation, the inner push button rotary knob assembly includes rotational movement about z-axis  40  and translational travel along z-axis  40 . As such, in at least one embodiment, the inner rotary knob  16  has the functionality of a push button. It may be depressed along z-axis  40  toward housing  25  independently of any rotational movement. The spring-like bias of snap dome  20  provides tactile feedback to a user upon depressing the inner push button rotary knob assembly to activate electronics  52  within housing  25 . The snap dome  20  springs back, forcing the push button to its former undepressed state. 
         [0028]    The angular and translational positions of magnet  22  with respect to z-axis  40  may be changed by sequentially depressing, rotating and releasing rotary knob  16 . The change may be determined by encoder  51  ( FIG. 5 ) which is disposed on the underside of cavity bottom  24   c . As one example, inner rotary knob  16  may be depressed and rotated by a desired angle Θ. The angle Θ may be determined by encoder  51  as the user wanting to activate function “A”, for example. In turn, encoder  51  may activate function “A” in the electronics  52 . As another example, a control function may be activated by depressing and releasing the inner push button rotary knob  16 . Upon depression and release, encoder  51  may detect a change in magnetic intensity, as the rotary knob is momentarily moved closer to encoder  51 . This magnetic change may be interpreted by encoder  51  as a desire to activate function “B”, for example. 
         [0029]    It will be appreciated that functions “A” and “B” may be any function needed to control electronics  52 . For example, function “A” may be “activate I.R. mode” and function “B” may be “on/off”. Similarly, the relative angular position of outer rotary knob  12  with respect to z-axis  40  may be changed by rotating the outer rotary knob. This change may be decoded, or interpreted, by encoder  50  ( FIG. 5 ) which is disposed on the underside of external boundary surface  24   f . For example, outer rotary knob  12  may be rotated around z-axis  40  by an angle Θ. The relative change in position of outer rotary knob  12  may be determined by encoder  51  as a desire to activate function “C”, for example. In turn, encoder  51  may activate function “C” within the electronics  52 . 
         [0030]      FIGS. 3 and 4  show exploded views of the dual independent push button rotary knob assembly  10  in relation to interface plate  24 , which sits on top of housing  25 . As shown, magnet  22  may be inserted into a bore of inner rotary knob  16 . Magnet strip  18  may be inserted into a circumferential slot of outer rotary knob  12 . Dust shield  30  may then be inserted into outer rotary knobs  12  from the top. Retention ring  26  and o-ring  28  may be inserted into outer rotary knob  12  from the bottom, followed by inserting inner rotary knob  16 . 
         [0031]    The snap dome  20  may be placed within a cavity  24   e  of boss  24   b  beneath magnet  22  and push button  16  ( FIG. 2 ). As already described, snap dome  20  provides tactile feedback for the user when inner push button rotary knob  16  is depressed. 
         [0032]    The outer rotary knob  12  includes circumferentially arranged retention features  12   b  which may fasten to boss  24   b  by way of circumferential slot  24   d . The mating slot  24   d  circumferentially accepts retention features  12   b , thereby capturing dual independent push button rotary knob assembly  10  to housing  25 . 
         [0033]      FIG. 5  is a cross-sectional view of an embodiment of the present invention zo showing the relationship between encoders  50  and  51  and dual independent push button rotary knob assembly  10 , the latter including magnets  22  and  18 . The encoders  50  and  51  are disposed entirely within housing  25  and are separated from push button rotary knob assembly  10  by interface plate  24  at external boundary surface  24   f  and cavity bottom  24   c , respectfully. The rotational and translational positions of magnet  22  are magnetically sensed by encoder  51  without any direct contact. Similarly, the rotation of magnetic strip  18  is magnetically sensed by encoder  50  without any direct contact. This provides contactless communication between the magnets and their respective encoders. 
         [0034]    Because of its contactless communication capability, the dual independent push button rotary knob assembly  10  is ideally suited for harsh environments. It is reliable and immune from adverse environmental conditions, such as dust, moisture, vibration and electromagnetic interference. The magnet  22  and encoder  51  may be separated across cavity bottom  24   c  by a thickness T that may vary between 0.5-1.8 mm, for example. The magnetic strip  18  and encoder  50  may similarly be separated across external boundary surface  24   f  by a thickness T that may vary between 0.5-1.8 mm, for example. 
         [0035]    Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.