Abstract:
The present invention is a structure for attaching a remote control to a steering wheel using a holder, to allow the positions of operation buttons and text display positions of an operation surface to be set up freely, taking into account visibility and operability for the user. The remote control and the holder are formed so that they can engage with each other. An angle adjustment engagement section is formed on the engagement sections thereof. The angle adjustment engagement section is formed from an external gear engagement section formed on the remote control and an internal gear engagement section formed on the holder. The engagement positions of the external gear and internal gear are used to perform angle adjustments around central axes, which form a shared axis. The operation surface of the remote control is formed roughly perpendicular to the center axis.

Description:
INCORPORATION BY REFERENCE  
       [0001]     The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2005-136287 filed on May 9, 2005. The content of the application is incorporated herein by reference in its entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to an attachment structure for attaching a remote controller (hereinafter referred to as a remote control) to a support member (e.g., the steering wheel of an automobile).  
         [0003]      FIG. 9  shows a known example of a structure for attaching a remote control to a steering wheel in which a remote control  101  is attached to the wheel  1  using a securing band  103 . Wheel  1  is equipped with a central section  11 , rod-shaped spokes  12  projected radially from the central section  11 , and a circular grip  13  connected to the ends of the spokes  12 .  
         [0004]     Also shown is an instrument panel  105 , a navigation device  107 , a monitor  109  of the navigation device  107 , and a switch  111 . When the switch  111  is pressed and a signal such as an infrared beam is emitted from a light-emitting section of the remote control  101 , the signal is received by a light-receiving section of the monitor  109  and is sent to a control module of the navigation device  107 .  
         [0005]     With the conventional example shown in  FIG. 9 , the securing band  103  can be used to change the position at which the remote control  101  is attached to the steering wheel  1 . However, since the attachment position of the remote control  101  must not obstruct driving operations and field of view, it is not possible to attach the remote control  101  so that it is oriented properly relative to the light-receiving section of the monitor  109 .  
         [0006]     In order to overcome the problem described above, there has been proposed a structure equipped with a holder attached to a steering wheel and a remote control attached to the holder in a manner that allows adjustment of the angle (e.g., see Japanese Laid-Open Patent Publication Number 2001-309466).  
         [0007]     However, with this technology, in order to orient the signal in an appropriate direction, the remote control is attached to the holder so that it is possible to adjust the angle around an axis parallel to the operation surface of the remote control (the surface with the operation buttons). Thus, it is not possible to freely design the position of the operation buttons or the text display position of the operation surface to take into account visibility and operability for the user.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0008]     The object of the present invention is to overcome the problems described above and to provide a remote control attachment structure that makes it possible to freely design the position of the operation buttons and the text display position of the operation surface, taking into account visibility and operability for the user.  
         [0009]     The invention provides a remote controller attachment structure for attaching a remote controller to a member using a holder wherein an engagement section engages with the remote controller and the holder. An angle adjustment engagement section is formed on the engagement section of the remote controller and holder allows positioning by aligning center axes so that angle-adjustable engagement is possible. Also, an operation surface of the remote controller is formed roughly perpendicular to the center axis.  
         [0010]     Another embodiment is that the angle adjustment engagement section is a gear-shaped engagement section with the engagement section of the remote controller and the holder being formed in a gear shape.  
         [0011]     A further embodiment includes the engagement section of the remote controller and the holder equipped with a cylindrical outer surface and inner surface that face each other and have aligned central axes. The gear-shaped engagement section includes an internal gear engagement section and an external gear engagement section. The internal gear engagement section is equipped with a plurality of internal gear teeth formed at a fixed pitch along a perimeter direction of an inner cylindrical surface of the holder. The external gear engagement section is equipped with a plurality of external gear teeth formed along a perimeter direction of an outer cylindrical surface of the remote controller and capable of being meshed with the inner gear teeth during engagement with the holder.  
         [0012]     The engagement section of the remote controller and the holder can also be equipped with a cylindrical outer surface and inner surface that face each other and have aligned central axes. The gear-shaped engagement section includes an internal gear engagement section and an external gear engagement section. The internal gear engagement section is equipped with a plurality of internal gear teeth formed at a fixed pitch along a perimeter direction of an inner cylindrical surface of the remote controller. The external gear engagement section is equipped with a plurality of external gear teeth formed along a perimeter direction of an outer cylindrical surface of the holder. The external gear teeth can be meshed with the inner gear teeth during engagement with the remote controller.  
         [0013]     Another embodiment of the invention provides a remote controller attachment structure where the angle adjustment engagement section is an interlocking engagement section formed with a projection and cavity at the engagement section of the remote controller and the holder.  
         [0014]     An embodiment of a remote controller attachment structure where the engagement section of the remote controller and the holder is equipped with a flat upper surface and lower surface facing each other and formed roughly perpendicular to the central axes. The interlocking engagement section can be formed from a concave engagement section and a convex engagement section. The concave engagement section is equipped with a plurality of cavities formed at a fixed pitch along a perimeter direction centered on an intersection point between the center axis and the upper flat surface of the holder. The convex engagement section is equipped with projections formed on the lower flat surface of the remote controller and engageable with the cavities during engagement with the holder.  
         [0015]     The invention provides a remote controller attachment structure where the engagement section of the remote controller and the holder can be equipped with a flat upper surface and lower surface facing each other and formed roughly perpendicular to the central axes. The interlocking engagement section can be formed from a concave engagement section and a convex engagement section. The concave engagement section is equipped with a plurality of cavities formed at a fixed pitch along a perimeter direction centered on an intersection point between the center axis and the lower flat surface of the remote controller. The convex engagement section is equipped with projections formed on the upper flat surface of the holder and engageable with the cavities during engagement with the remote controller.  
         [0016]     The invention provided above is a remote controller attachment structure where the member is a steering wheel of an automobile.  
         [0017]     An engagement section can engage with the remote controller and the holder is formed, so the remote control and the holder are engaged and aligned in an angle-adjustable manner around a center axis roughly perpendicular to the operation surface of the remote control. The operation button positions and text display positions on the operation surface of the remote control can be positioned in an angle-adjustable manner around the center axis along the same plane as the operation surface. Thus, the operation buttons and text display positions can be set up freely to take into account visibility and operability for the operator.  
         [0018]     The invention provides the angle adjustment engagement section in a gear-shaped engagement section with the engagement section of the remote controller and the holder being formed in a gear shape. The positioning angle can be easily adjusted and set up based on the number of gear teeth formed on the engagement section of the remote control and holder.  
         [0019]     The embodiment above provides the gear-shaped engagement section with an internal gear engagement section and an external gear engagement section. The internal gear engagement section can be equipped with a plurality of internal gear teeth formed at a fixed pitch along a perimeter direction of an inner cylindrical surface of either the holder or remote control. The external gear engagement section is equipped with a plurality of external gear teeth formed along a perimeter direction of an outer cylindrical surface of the remote controller or holder, opposite of the internal gear teeth and capable of being meshed with the inner gear teeth during engagement with the holder. The number of internal gear teeth formed on the inner cylindrical surface of the holder can be used to easily define the number of angle adjustment positions. The positioning angle can be adjusted by turning the remote control around the center axis by a predetermined angle.  
         [0020]     The invention provides the angle adjustment engagement section with an interlocking engagement section formed with a projection and cavity at the engagement section of the remote controller and the holder. The number of interlocking sections in the engagement section of the remote control and the holder can be used to easily define the adjustment angle for positioning.  
         [0021]     Another embodiment can form the interlocking engagement section from a concave engagement section and a convex engagement section. The concave engagement section can be equipped with a plurality of cavities formed at a fixed pitch along a perimeter direction centered on an intersection point between the center axis and the upper flat surface of the holder or the lower flat surface of the remote controller. The convex engagement section can be equipped with projections formed on the lower flat surface of the remote controller or on the upper flat surface of the holder. The projections are engageable with the cavities during engagement with either the holder or the remote controller. The adjustment angle for positioning can be easily defined based on the number of cavities formed on the upper flat surface of either the holder or the lower flat surface of the remote controller.  
         [0022]     An embodiment is that the member is a steering wheel of an automobile and the present invention can be used as a structure for attaching an automotive remote control. The positions for operations buttons and text display positions of the remote control can be set up freely, taking into account the visibility and operability for the automobile driver. Thus, the invention makes it easy to operate the switches in a tactile manner without visual feedback.  
         [0023]     The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]      FIG. 1  is an exploded perspective drawing showing an embodiment of the present invention with a section omitted;  
         [0025]      FIG. 2  is a plan drawing showing the attached state of an embodiment;  
         [0026]      FIG. 3  is a cross-section detail drawing along the  3 - 3  line in  FIG. 2 ;  
         [0027]      FIG. 4  is a cross-section detail drawing along the  4 - 4  line in  FIG. 2 ;  
         [0028]      FIG. 5  is a plan drawing showing the attached state of the above embodiment when the attachment position has been changed;  
         [0029]      FIG. 6  is a plan drawing showing the attached state of another embodiment of the present invention;  
         [0030]      FIG. 7  is a cross-section detail drawing along the  7 - 7  line in  FIG. 6 ;  
         [0031]      FIG. 8  is a plan drawing of  FIG. 6  with the remote control removed; and  
         [0032]      FIG. 9  is a drawing of the prior art. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0033]     An embodiment of the present invention is shown in  FIG. 1  through  FIG. 4 . The figures show an automobile steering wheel  1 , a remote control  2 , a holder  5 , a securing band  8 , and setscrews  9 . The steering wheel  1  is formed identical to the steering wheel  1  shown in  FIG. 9  and is equipped with central section  11 , spokes  12 , and grip  13 .  
         [0034]     The remote control  2  is equipped with a case  20  formed from a synthetic resin, and a circuit unit  40  housed and supported in the case  20 .  
         [0035]     The case  20  is formed from an upper case  21 , a lower case  22 , and a bottom cover  23 , which can be engaged integrally.  
         [0036]     The case  21  is equipped with a roughly cylindrical body  24  and a disk-shaped upper plate  25  that seals the upper surface of the body  24 . On the upper plate  25 , there are formed through-holes  26  at the center, the inner perimeter, and the outer perimeter to allow the heads of operation buttons  45 , described later, to be passed through and projected. Thus, the upper surface of the upper plate  25  corresponds to the operation surface of the remote control  2 .  
         [0037]     The lower case  22  is formed with a roughly cylindrical outer shape with a collar  27  projecting outward from the central section thereof. A body  28  engages with the body  24  of the upper case  21  above the collar  27 . The body  28  can be formed with an outer diameter that tapers downward. An engagement groove  29  is formed along the outer perimeter continuous with the collar  27 .  
         [0038]     An external gear engagement section  30  is formed on the lower case  22  below the collar  27 . The outer shape of the external gear engagement section  30  is formed as a cylinder with multiple external gear  31  being formed on the outer perimeter of the cylindrical surface at a fixed pitch along a perimeter direction. A central axis C 1  of the external gear engagement section  30  passes roughly through the center of the upper plate  25  and is roughly perpendicular to the plane of the upper plate  25 .  
         [0039]     A circuit unit  40  is equipped with a substrate  41  formed with a predetermined circuit pattern, switches  42  mounted on the substrate  41 , and circuit elements such as LED  43 . Operation buttons  45  of the switches  42  are projected outward from the operation surface so that the heads thereof can pass through the through-holes  26 - 26  of the upper plate  25 .  
         [0040]     The heads of the operation buttons  45  can be marked with the numbers “ 1 ”-“ 12 ” corresponding to the functions assigned to the operation buttons.  
         [0041]     In order to facilitate tactile operations, projections  46  are formed on the heads of the operation buttons  45  corresponding to the respective identifications “ 1 ”, “ 4 ”, “ 7 ”.  
         [0042]     The holder  5  is formed from a main holder unit  50  shaped from synthetic resin and a holder cover  70 . The main holder unit  50  is equipped with an abutment piece  51  that abuts against the steering wheel  1 , an internal gear engagement section  52  that can engage with the external gear engagement section  30  of the remote control  2 , and a connecting section  53  connecting the abutment piece  51  and the internal gear engagement section  52 .  
         [0043]     The external gear engagement section  30  and the internal gear engagement section  52  form a gear engagement section  60  that serves as an angle adjustment engagement section.  
         [0044]     The curvature of the inner surface of the abutment piece  51  that abuts the grip  13  is formed to be roughly the same as the curvature of the grip  13  so that there can be a tight fit with a section of the grip  13  of the steering wheel  1 . A cut-out  35  is formed at the center of the upper portion of the abutment piece  51 .  
         [0045]     A pair of engagement claws  55 ,  56  are projected outward from either side of the abutment piece  51  above and below the perpendicular axis (the up/down axis in  FIG. 1 ).  
         [0046]     The internal gear engagement section  52  is formed in a ring shape (a short cylindrical shape) with multiple inner gear teeth  57  formed along the perimeter direction of the inner cylindrical surface thereof.  
         [0047]     A center axis C 2  of the inner gear engagement section  52  is aligned with a center axis C 1  of the external gear engagement section  30  during engagement with the external gear engagement section  30 .  
         [0048]     The connecting section  53  is equipped with a horizontal connecting section  61  and a vertical connecting section  62 . Insertion holes  63  are formed around the horizontal connecting section  61  to allow insertion of a securing handle  8 , and bosses  65  formed with threaded holes  64  for the setscrews  9  are projected. The insertion holes  63  also serve as escape holes for the lower engagement claws  56 .  
         [0049]     The holder cover  70  is equipped with a main cover unit  71  covering the section of the main holder unit  50  above the connecting section  53 . An engagement projection  72  is projected from the lower section of the main cover unit  71 .  
         [0050]     The main cover unit  71  is formed with attachment holes  73  for insertion of the threaded sections of the setscrews and for preventing the head from slipping out. The main cover unit  71  is also formed with cut-outs  75  for insertion of securing handles  8 .  
         [0051]     The engagement projection  72  is formed roughly as a semicircular ring to allow engagement with roughly half the perimeter of the engagement groove  29  of the lower case  22 . The radial section of the engagement projection  72  is downwardly tapered from the outer perimeter to the inner perimeter.  
         [0052]     The securing handle  8  is used to attach the holder  5  to the steering wheel  1  and is formed as a band from a material, e.g., synthetic rubber or any other suitable material, having ample stretchability. Elliptical engagement holes  81  are formed along the longitudinal axis thereof.  
         [0053]     Next, the attachment of the remote control  2  to the steering wheel  1  using the holder  5  and the securing handle  8  will be described.  
         [0054]     Using the securing handle  8 , the main holder unit  50  is secured to a preferred position of the grip  13  of the steering wheel  1 .  
         [0055]     For example, as shown in  FIG. 2 , if the main holder unit  50  is to be attached to a central section of the left side of the grip  13  of the steering wheel  1 , the abutment piece  51  of the main holder unit  50  is pressed against the corresponding section of the grip  13 , the engagement holes  81  on one side of the securing handles  8  are engaged with the engagement claws  55 , the securing handles  8  are wrapped around the corresponding section of the grip  13 , the corresponding engagement holes  81  on the other side are engaged with the engagement holes  56  while stretching the securing handle  8 , thus firmly attaching the main holder unit  50  to the steering wheel  1 .  
         [0056]     Next, the remote control  2  is aligned so that the text display position, including the numbers “ 1 ”-“ 2 ”, etc. of the operation buttons  45  of the remote control  2  are at a preferred position for the driver. The external gear engagement section  30  of the remote control  2  is engaged with the internal gear engagement section  52  of the main holder unit  50 . For this positioning, the angle around the central axis C 1  can adjusted over multiple steps by changing the meshing positions of the external gear  31  of the external gear engagement section  30  and the internal gear  57  of the internal gear engagement section  52 .  
         [0057]     For example, to position the operation buttons  45 , as shown in  FIG. 2 , the external gear engagement section  30  of the remote control  2  can be engaged with the internal gear engagement section  52  of the main holder unit  50  so that the operation button  45  that is printed with “ 1 ” is at the top.  
         [0058]     Further, the main holder unit  50  is covered with the holder cover  70  and the stopping screws  9  are screwed into the threaded hole  64  of the main holder unit  50 . Thus, this secures the remote control  2  to the holder  5 . More specifically, the main cover unit  71  of the holder cover  70  covers the section above the connecting section  53  of the main holder unit  50 . The engagement projection  72  of the holder cover  70  engages with the engagement groove  29  of the main holder unit  50 , stopping screws  9  are screwed into threaded holes  64  of the main holder unit  50  through the attachment holes  73  and interposing washers  91  and spring washers  92 , resulting in the remote control  2  being secured to the holder  5 .  
         [0059]     The embodiment described above presents an example in which the remote control  2  is attached to the center of the left side of the grip  13 , but the present invention is not restricted to this. For example, attachment can be performed at the right side, top side, bottom side, or the like of the grip  13  of the steering wheel  1 .  
         [0060]     For example, as shown in  FIG. 5 , the remote control  2  can be attached to the center of the right side of the grip  13  of the steering wheel  1 .  
         [0061]     In the embodiment described above, the number of the external gear  31 ,  31  of the external gear engagement section  30  and the number of internal gear  57 ,  57  of the internal gear engagement section  52  are made identical in order to improve and stabilize the engagement between the remote control  2  and the holder  5 . However, the present invention is not restricted to this. Similar angle adjustments can be made in cases where the teeth count on one side is less than the teeth count on the other side.  
         [0062]     For example, external gear count of the external gear engagement section can be one half the internal gear count of the internal gear engagement section, with the external gear pitch being twice the internal gear pitch.  
         [0063]     In the embodiment described above, the internal gear engagement section is formed on the holder and the external gear engagement section is formed on the remote control. However, the present invention is not restricted to this, and it is possible for the external gear engagement section to be formed on the holder and for the internal gear engagement section to be formed on the remote control.  
         [0064]     For example, concave grooves extending along the center axis C 2  can be formed at a fixed pitch along the perimeter of the inner cylindrical surface of the engagement section of the holder, and ridges can be formed that engage with the concave grooves of the holder in a manner that allows angle adjustment when engaged with the holder (a ridge extending along the center axis C 1 ).  
         [0065]     In the embodiment described above, the internal gear engagement section is formed on either the holder or the remote control and the external gear engagement section is formed on the remaining element. However, the present invention is not restricted to this, and it would be possible to form multiple cavities at a fixed pitch along the perimeter direction on the engagement surface (cylindrical surface) of either the holder or the remote control, with projections that can be engaged with these cavities formed on the remaining element.  
         [0066]     Another embodiment of the present invention is shown in  FIG. 6  through  FIG. 8 . These figures show a steering wheel  1 , a remote control  2   a,  a holder  5   a,  and a securing band  8   a.  Remote control  2   a  is equipped with a case  28  formed in a roughly cylindrical shape and a circuit unit  48  housed in a case  20   a.  Case  20   a  is formed from an upper case  21   a  and a lower case  22   a  and a bottom cover (e.g., a battery cover)  23   a.    
         [0067]     The upper surface of an upper plate  25   a  of the upper case  21   a  corresponds to the operation surface of the remote control  2   a,  and the heads of operation buttons  45   a  can pass through the upper plate  25   a  and are projected outward.  
         [0068]     The upper section of the lower case  22   a  is engaged with the upper case  21   a  and the lower section is formed so that the outer diameter is tapered downward. The bottom cover  23   a  engages with the bottom surface of the lower case  22   a  and is formed roughly in a disc shape. An engagement projection  30   a  is formed on the bottom surface of the bottom cover  23   a.    
         [0069]     The engagement projection  30   a  is formed from roughly hemispherical projections  31   a  projected downward from the bottom surface of the bottom cover  23   a.  The projections  31   a  can be formed at a fixed pitch in the perimeter direction around the center axis C 1 , which passes through roughly the center of the bottom cover  23   a  and is roughly perpendicular to the plate surface of the bottom cover  23   a.    
         [0070]     The holder  5   a  is equipped with a main holder unit  50   a  formed roughly in a disc-shape, and an abutment piece  51   a  connected to the main holder unit  50   a  and that tightly fits against the grip  13 , and a connecting section  53   a  that connects the two elements.  
         [0071]     On the upper surface of the main holder unit  50   a  is formed a concave engagement section  52   a  that engages with the engagement projection  30   a  of the remote control  2   a  in a manner that allows angle adjustment.  
         [0072]     The convex engagement projection  30   a  and the concave engagement section  52   a  form an interlocking engagement section  60   a  that serves as an angle adjustment engagement section.  
         [0073]     The concave engagement section  52   a  is formed from hemispherical cavities  57   a  on the upper surface of the main holder unit  50   a.  As shown in  FIG. 8 , the cavities  57   a  are formed at a fixed pitch along the perimeter direction and around a central axis C 2 , which passes through roughly the center of the main holder unit  50   a  and is roughly perpendicular to the plate surface of the main holder unit  50   a.    
         [0074]     The central axes C 1 , C 2  are identical when the convex engagement section  30   a  of the remote control  2   a  and the concave engagement section  52   a  of the holder  5   a  are engaged and aligned and angle-adjusted.  
         [0075]     Leaf spring engagement pieces  54  are projected upward from the ends of the upper surface of the main holder unit  50   a  (the upper and lower ends in  FIG. 8 ). Engagement claws  54   a  are formed at the free ends of the engagement pieces  54  and engaged with engagement holes (not shown in the figures) formed on the side wall of the lower case  22   a  when the lower case  22   a  is engaged.  
         [0076]     In the embodiment described above, the number of projections  31   a  of the convex engagement section  30   a  is identical with the number of cavities  57   a  of the concave engagement section  52   a  in order to improve and stabilize the engagement between the remote control  2   a  and the holder  5   a.  However, the present invention is not restricted to this, and similar angular adjustments can be made even if the number of one is less than the number of the other.  
         [0077]     For example, the number of projections of the convex engagement section can be one-half the number of cavities of the concave engagement section, with the pitch between projections being twice the pitch between cavities.  
         [0078]     In the embodiment described above, the convex engagement section  30   a  is formed on the bottom cover  23   a  of the case  20   a,  and the convex engagement section  52   a  is formed on the main holder unit  50   a.  However, the present invention is not restricted to this, and it is possible to form the concave engagement section on the bottom cover  23   a  of the case  20   a,  and the convex engagement section on the main holder unit  50   a.    
         [0079]     In the embodiment described above, the concave engagement section is formed on either the holder or the remote control, and the convex engagement section is formed on the remaining element. However, the present invention is not restricted to this, and it is possible to form multiple radial concave grooves at a fixed pitch around an intersection with the central axis on the engagement surface (abutment plane) of either the holder or the remote control, while forming on the remaining element ridges that can engage with these concave grooves. The multiple radial concave grooves and the ridges that engage therewith can also be used if engagement takes place with a gear shape along the perimeter direction.  
         [0080]     In order to simplify the descriptions, in the previous embodiments, no text or numerals are printed on the operation surface of the remote controls  2 ,  2   a  and the heads of the operation buttons  45 ,  45   a  are printed with the numbers “ 1 ”-“ 12 ”. However, the present invention is not restricted to this, and it would be possible to print text, numerals, symbols, or the like on the operation surfaces of the remote controls  2 ,  2   a  and/or text, numerals, or symbols can be printed on the operation buttons  45 ,  45   a.    
         [0081]     For example, the numbers “ 1 ”-“ 5 ” on the heads of the operation buttons  45 ,  45   a  of the remote controls  2 ,  2   a  can be changed to “Destination”, “Talk” etc., the numbers “ 6 ”, “ 7 ” can be changed to the symbols “−” or “+”, and the number “ 12 ” can be changed to “Run.” 
         [0082]     In the embodiments described above, the remote controls  2 ,  2   a  are attached to the grip  13  of the steering wheel  1 . However, the present invention is not restricted to this, and it would be possible to attach the remote control to the spoke of the steering wheel  1 .  
         [0083]     In the embodiments, the engagement sections of the remote control and the holder are formed with cylindrical shapes. However, the present invention is not restricted to this, and it would also be possible for the engagement sections of the remote control and the holder to be formed as polygonal cylinders.  
         [0084]     For example, it would also be possible to use the present invention when the engagement section of the remote control and the holder are formed as an cuter surface and an inner surface of facing polygonal cylinders with matching central axes. In this case, there is no need to form a gear shape on the engagement surfaces.  
         [0085]     In the above embodiments, the attachment is performed on the steering wheel, but it would also be possible to perform attachment on an element other than the steering wheel.  
         [0086]     Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.