Abstract:
In a preferred embodiment, a compact, low-cost, rotary control knob assembly, including: an indicator portion having disposed thereon indicia representing selectable settings of the control knob assembly; a knob portion disposed over the indicator portion, such that the indicia are contained within a perimeter-defined area of the knob portion; and an indicator opening defined through the knob portion, which indicator opening is selectively alignable with ones of the indicia by rotation of the knob portion with respect to the indicator portion.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to rotary control knobs generally and, more particularly, but not by way of limitation, to a novel, compact, low-cost, rotary control knob and indicator. 
     2. Background Art 
     Rotary control knobs are used in a variety of applications. While the present invention is described, for illustrative purposes only, as being applied to rotary control knobs in a vehicle, it will be understood that rotary control knobs of the present invention may be applied to any use in which it is desired to graphically represent the setting of a rotary control knob. 
     In vehicle applications, rotary knobs are employed, for example, to control environmental air flow and temperature in the vehicle operator/passenger compartment. Typically, such a control knob has a pointer that indicates the setting of the control knob by pointing to a control setting represented graphically on an arcuate scale circumjacent the knob. The pointer and the scale are illuminated by backlighting at night when the lights of the vehicle are turned on. Such a conventional control knob is typically injection molded of thermoplastic materials and is relatively expensive to manufacture, since it requires the use of either a multistep molding process or the injection of two or more separate different colored or clear materials in a single mold. 
     A single-material control knob can be fabricated in which the pointer is not backlighted, but, rather, the pointer extends from the periphery of the control knob and covers a desired setting on the graphical scale. With this arrangement, of course, one cannot view the setting that is covered. In some cases, the setting can be inferred from adjacent, non-covered settings, but, in other cases, it cannot. 
     With both of the above conventional rotary control knobs, the area required for the total layout comprises the area of the knob and the surrounding graphical representation. In some cases, this area consumed is less compact than is desirable. 
     Accordingly, it is a principal object of the present invention to provide a rotary control knob which is cast of a single material, but which can be backlighted. 
     It is a further object of the invention to minimize the area that a rotary control knob and the accompanying graphical representation consume, preferably no more than the area of the knob itself. 
     It is an additional object of the invention to provide such a rotary control knob which can be economically manufactured using conventional techniques known in the art. 
     Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures. 
     SUMMARY OF THE INVENTION 
     The present invention achieves the above objects, among others, by providing, in a preferred embodiment, a compact, low-cost, rotary control knob assembly, comprising: an indicator portion having disposed thereon indicia representing selectable settings of said control knob assembly; a knob portion disposed over said indicator portion, such that said indicia are contained within a perimeter-defined area of said knob portion; and indicating means defined through said knob portion, which indicating means is selectively alignable with ones of said indicia by rotation of said knob portion with respect to said indicator portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Understanding of the present invention and the various aspects thereof will be facilitated by reference to the accompanying drawing figures, submitted for purposes of illustration only and not intended to define the scope of the invention, on which: 
     FIGS. 1 and 2 are fragmentary isometric view of conventional rotary control knobs and associated graphical representations. 
     FIG. 3 is a fragmentary, exploded isometric view showing the elements of a rotary control knob according to the present invention. 
     FIG. 4A is a top plan view showing one type of graphical representation for use in a rotary control knob according to the present invention. 
     FIG. 4B is a top plan view showing one setting of a rotary control knob with the graphical representation of FIG.  4 A. 
     FIG. 4C is a top plan view showing another setting of the rotary control knob with the graphical representation of FIG.  4 A. 
     FIG. 5 is a top plan view showing another rotary control knob according to the present invention. 
     FIGS. 6 and 7 are isometric views of further alternative rotary control knobs according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference should now be made to the drawing figures, on which similar or identical elements are given consistent identifying numerals throughout the various figures thereof, and on which parenthetical references to figure numbers direct the reader to the view(s) on which the element(s) being described is (are) best seen, although the element(s) may be seen also on other views. 
     FIG. 1 illustrates one type of conventional rotary control knob arrangement, generally indicated by the reference numeral  10 , mounted in a panel  12  which panel may be assumed to be, for example, the dashboard of a vehicle and the arrangement may be assumed to be, for example, a ventilation air flow control. A rotary control knob  16  is rotatably mounted in panel  12  and includes thereon an indicator or pointer  18  which selectively points to one of the control settings indicated on graphics, as at  20 , circumjacent knob  16  and disposed on panel  12  by conventional means. Pointer  18  and graphics  20  are clear or semi-translucent so as to render them susceptible to backlighting illumination by means not shown. It will be understood that knob  16  is connected to a shaft or other such means (none shown) to selectively control a switch (not shown). 
     In order that pointer  18  may be backlighted or otherwise highlighted by backlighting, it is necessary that the materials of the pointer and knob  16  be different so that there is a difference in color between the pointer and the knob. As noted above, this requires employing either a multiple-step molding process or a complicated two-material, single-step molding process. In some cases, a third material is used for the perimeter of knob  16  to enhance manual grasping thereof. As an alternative manufacturing process, the various elements may be separately produced and then subsequently joined. 
     FIG. 2 illustrates another type of conventional rotary control knob arrangement, generally indicated by the reference numeral  10 ′, and mounted in a panel  12 ′. Here, a rotary control knob  16 ′ includes a pointer  18 ′ that extends from the periphery of the knob and selectively covers graphics, as at  20 ′. Rotary control knob  16 ′ and pointer  18 ′ can be molded of a single material in a single step; however, pointer  18 ′ cannot be backlighted and there is the further disadvantage that a portion of graphics  20 ′ is covered. 
     FIG. 3 illustrates the elements of a rotary control knob assembly, constructed according to the present invention, and generally indicated by the reference numeral  30 . Knob assembly  30  includes a generally hollow, cylindrical knob portion  32  having an end face  34  extending across and partially closing the upper end thereof, the end face having a plurality of openings defined therethrough, as at  36 . A shaft  40 , fixedly attached to the rear surface of end face  34  extends rearwardly therefrom coaxial with knob portion  32 . It will be understood that shaft  40  will be connected to a control element (not shown) which may be assumed to be, for example, an environmental ventilation air control switch in a vehicle. End face  32  includes a diamond-shaped pointer opening  42  defined therethrough. 
     Rotary control assembly  30  also includes a generally hollow, cylindrical indicator portion  50  having an end face  52  extending across and partially closing the upper end thereof, the end face having a central opening  54  defined therethrough such that shaft  40  can be inserted through the central opening. End face includes disposed thereon by conventional means graphic indicia, as at  56 , to indicate the position of knob portion  32  when the knob portion is disposed over indicator portion  50 . Indicator portion  50  is fixedly attached to a panel  60  which panel may be assumed to be a portion of the dashboard of a vehicle. 
     A source of backlighting  66  is disposed so as to backlight graphic indicia  56  and pointer opening  42 . An annular ring  70  may be disposed around central opening  54  in the path from light source  66  to pointer opening  42  to provide the pointer opening with a selected color. Alternatively, annular ring  70  may be omitted and pointer opening  42  illuminated directly from light source  66 . 
     When assembled, knob portion  32  will fit over indicator portion  50  and will be rotatably secured in that position by means of the attachment of shaft  40  to the control element (not shown). 
     It will be understood that knob portion  32  can be economically manufactured of one material in a conventional one-step molding process from a suitable thermoplastic material. Indicator portion  50  may be similarly manufactured. It will be noted that having graphic indicia  56  disposed within the outer periphery of knob portion  32  reduces the total area required by knob assembly  30  compared with conventional rotary control knobs (FIGS.  1  and  2 ). This offers greater compactness for control clusters and a cleaner, more streamlined appearance. A further advantage of the compactness of knob assembly  30  is that the area and/or number of the backlighting means can be reduced. 
     FIG. 4A illustrates an indicator portion end face  80  which may be assumed to be, for example, part of a vehicle environmental ventilation air control. End face  80  has disposed thereon graphic indicia including an icon  82  indicating air flow from a dashboard vent, an icon  84  indicating air flow at floor level, and an icon  86  indicating air flow to a windshield defroster. Intermediate settings are indicated by circles, as at  88 . Icons  82 ,  84 , and  86  and circle  88  can be backlighted by suitable means (not shown). A central opening  90  is provided for the insertion therethrough of a shaft such as shaft  40  (FIG.  3 ). Surrounding central opening  90  is an annular translucent ring  92  having a blue segment  94  and a red segment  96 . 
     FIG. 4B illustrates a knob end face  100  having defined therethrough a pointer opening  102 , a relative small oval opening  104  through which is visible with which one of the graphic indicia the pointer opening is aligned, and a relatively large arcuate opening  106  through which are visible the rest of the graphic indicia. In the orientation shown, pointer opening  102  is aligned with icon  86  and, in this position, the pointer opening will be aligned with red segment  96  and will, therefore, appear red, indicating a heating mode. 
     FIG. 4C illustrates knob end face  80  rotated to a position in which pointer opening  102  is aligned with icon  82 . In this position, the pointer opening will appear to be blue by virtue of the fact that it is disposed over segment  94  (FIG.  4 A), indicating a cooling mode. It will be understood that knob end face  100  may be similarly rotated to any of the intermediate positions indicated by circles  88 . 
     FIG. 5 illustrates a knob end face  120  disposed over an indicator end face  122  in an assembly which may be assumed to be, for example, part of a environmental temperature control system in a vehicle. Indicator end face  122  includes disposed thereon a blue band  130  and a red band  132 , the bands expanding in width in proportion to the distance from a neutral position  134  and representing, respectively, increasing level of cooling or heating. Knob end face includes defined therethrough a triangular-shaped pointer opening  140 , a relatively small oval opening  142  through which is visible the portion of graphics on indicator end face  122  with which the pointer opening is aligned, and two relatively large arcuate openings  144  and  146  through which are visible the rest of the graphic indicia on indicator end face  122 . 
     FIG. 6 illustrates another embodiment of a control knob assembly, generally indicated by the reference numeral  160 , and constructed according to the present invention. Assembly  160  includes a knob portion  162  with an end face  164  disposed over an indicator end face  166 , knob end face  164  including a triangular-shaped pointer opening  168  defined therethrough. The principal difference between assembly  160  and previously described embodiments is the provision of a circular opening  170  which highlights the graphic indicia on indicator end face  166  with which pointer opening  168  is aligned. In this embodiment, pointer opening  168  may be eliminated. 
     FIG. 7 illustrates yet another embodiment of a control knob assembly, generally indicated by the reference numeral  180 , and constructed according to the present invention. Assembly  180  includes a knob portion  182  with an end face  184  disposed over an indicator end face  186 , knob end face  184  including a triangular-shaped pointer opening  188  defined therethrough. The principal difference between assembly  180  and previously described embodiments is that pointer opening  188  points inwardly toward indicia on indicator end face  186 , while the pointer openings in the previously described embodiments point outwardly toward the indicia on the indicator end face. 
     It will thus be seen that the objects set forth above, among those elucidated in, or made apparent from, the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown on the accompanying drawing figures shall be interpreted as illustrative only and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.