Abstract:
A master light switch for a ground vehicle includes an actuator rotatably mounted to a housing. A switching contact is axially movably mounted to the actuator to rotate with the actuator. A plurality of circuit contacts faces the switching contact wherein different circuit contacts are electrically connectable by the switching contact depending on the rotary position of the actuator. A spring element urges the switching contact axially towards the circuit contacts to make contact between the switching contact and a circuit contact. A lift-and-set formation is arranged between the housing and the switching contact to axially displace the switching contact from a circuit contact during rotary movement of the actuator and to release the switching contact at a defined rotary position of the actuator to be axially urged by the spring element to axially move to make electrical contact between the switching contact and a circuit contact. A locking mechanism prevents turning of the actuator unless the locking mechanism is released. The locking mechanism is releasable and the actuator is turnable by one hand of a vehicle driver.

Description:
This application claims the benefit of U.S. Provisional Application Ser. No. 60/685,782 filed May 31, 2005. 
    
    
     BACKGROUND OF THE INVENTION 
     The military version of the common vehicle headlight switch, referred to as the “Main Lighting Switch” or MLS (p/n: MS-51113) consists of three levers: one for selecting panel lights, one for the selecting service drive lights and blackout lights, and one for a lockout function. The lockout prevents accidental turn on of the service drive lights. Designed in the 1950s, the switch can&#39;t be seen at night without a flashlight, so there is always the possibility of accidentally turning on the headlights during nighttime military operations. Additionally, the elongated levers are vulnerable to breakage. 
     The present inventor recognizes that it would be desirable to provide a master light switch that is cost effectively manufactured, had ergonomically convenient controls, is electrically reliable against shorts and power surges and reliable under a wide range of operating conditions and temperatures for military operations, and is effectively operable under military conditions. 
     SUMMARY OF THE INVENTION 
     The invention provides a master light switch for a ground vehicle that includes a housing, an actuator such as a knob or lever, a switching contact, a plurality of circuit contacts, a spring element and a lift-and-set formation. The actuator is rotatably mounted to the housing. The switching contact is axially movably mounted to the actuator to rotate with the actuator. The plurality of circuit contacts faces the switching contact wherein different circuit contacts are electrically connectable by the switching contact depending on the rotary position of the actuator. The spring element urges the switching contact axially towards the circuit contacts to make contact between the switching contact and a circuit contact. The lift-and-set formation is arranged between the housing and the switching contact to axially displace the switching contact from a circuit contact during rotary movement of the actuator and to release the switching contact at a defined rotary position of the actuator to be axially urged by the spring element to axially move to make electrical contact between the switching contact and a circuit contact. 
     Preferably, the lift-and-set formation comprises at least one roller rotatably mounted on the housing, and a cam hub mounted with the switching contact to be axially movable therewith and to rotate with the actuator. The cam hub has at least one cam surface engageable with the roller to define an advanced position wherein the switching contact makes contact with a circuit contact, and a retracted position wherein the switching contact is displaced from the circuit contact, as the cam surface passes over the roller. The spring element acts between the housing and the cam hub. 
     Preferably, the at least one roller comprises a plurality of rollers and the cam hub comprises a plurality of cavities defining a plurality of cam surfaces. In-this way, a plurality of switch positions can be defined by the rollers and cam surfaces. 
     Preferably, the master light switch comprises a further switching contact. The lift-and-set formation is arranged between the housing and the further switching contact to axially displace the further switching contact from the circuit contact during rotary movement of the actuator and to release the further switching contact at a defined rotary position of the actuator to be axially urged by the spring to axially move to make electrical contact between the further switching contact and a circuit contact. A rotor is mounted to the cam hub, the rotor carrying the switching contact and the further switching contact at rotary offset positions, to define two different switching configurations selectable using the actuator. 
     Preferably, the switching contact and/or the further switching contact is movably mounted to the rotor in a direction toward and away from a circuit contact, and comprising a further spring element located between the rotor and the switching contact. The further spring element provides for a resilient contact pressing between the switching contact and a selected one or more circuit contacts. 
     Preferably, the actuator comprises a lens therethrough, and the master light switch comprises a lighting element arranged between the switching contact and the actuator. The lighting element is arranged to beam light through the lens to illuminate a portion of the actuator. 
     According to another aspect of the invention, a master light switch for a ground vehicle is provided that includes a housing, an actuator rotatably mounted to the housing, a switching contact, a plurality of circuit contacts, and a locking mechanism. The actuator is rotatably mounted to the housing. The switching contact is axially movably mounted to the actuator to rotate with the actuator. The plurality of circuit contacts faces the switching contact, wherein different circuit contacts are electrically connectable by the switching contact depending on the rotary position of the actuator. The locking mechanism prevents turning of the actuator unless the locking mechanism is released. The locking mechanism is releasable and the actuator is turnable by one hand of a vehicle driver. 
     Preferably, the actuator includes a grippable outer part and a base part, the grippable outer part being mounted for sliding movement on the base part from a first position to a second position. The locking mechanism comprises a locking element mounted to the grippable outer part that engages the housing when the grippable outer part is in the first position to prevent turning of the actuator. The locking element is releasable when the grippable outer part is slid to the second position. 
     Preferably, the locking element comprises a pin and the housing comprises at least two teeth that releasably capture the pin between the two teeth. 
     Preferably, at least one of the teeth comprises an oblique surface facing the pin to allow forced rotation of the actuator in a first direction wherein the pin slides along the oblique surface, and wherein at least one of the teeth comprises a perpendicular surface which blocks movement of the pin and does not allow forced rotation of the actuator is a second direction. 
     The present Invention is designed to overcome the deficiencies of the prior art discussed above. The preferred embodiment of the present invention provides a switch that may provide some or all of the following advantages:
         1. The switch integrates the locking mechanism with the main knob, lever, button etc., that will allow to the driver to operate the switch with one hand;   2. The switch incorporates a roller, ball, or other type of antifriction bearing-based switch kinematics that will allow substantially reducing wear of the contacts and increase the lifetime of the switch;   3. The switch provides internal, self-sufficient illumination of the front panel as well as the controls, including but not limited to: buttons, knobs, levers of the switch to enable use in the dark; and   4. The switch can be manufactured at a comparatively low cost.       

     Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a front perspective view of a master light switch of the present invention; 
       FIG.  1 AA is a rear perspective view of the master light switch of  FIG. 1A ; 
       FIG.  1 AB is a plan view of the master light switch shown in  FIG. 1A ; 
         FIG. 1B  is an enlarged perspective exploded view of the master light switch of  FIG. 1A  with the housing  14 removed to view inside parts; 
         FIG. 1C  is a cross section taken generally along line  1 C- 1 C of  FIG. 1A ; 
       FIG.  1 CC is an elevational view of a main switch assembly removed from the remaining portions of the master light switch for clarity of description; 
         FIG. 1D  is a perspective view of an auxiliary rotor assembly taken from  FIG. 1B ; 
       FIG.  1 DD is a sectional view taken generally along line  1 DD- 1 DD of  FIG. 1D ; 
         FIG. 1E  is a perspective view of a main rotor assembly taken from  FIG. 1B ; 
       FIG.  1 EE is a sectional view taken generally along line  1 EE- 1 EE of  FIG. 1E ; 
         FIG. 1F  is a plan view of a contact board taken from  FIG. 1B  with some components as an example; 
       FIG.  1 FF is an elevational view of the contact board of  FIG. 1F ; 
         FIGS. 2A-2F  are fragmentary plan and elevational views illustrating a main switch assembly and its work principle; 
         FIG. 3A  is an exploded, fragmentary perspective view illustrating a lock mechanism and its work principle; 
         FIG. 3B  is a fragmentary sectional view of the lock mechanism of  FIG. 3A  illustrating its work principle; 
         FIG. 3C  is a fragmentary, plan view of the lock mechanism of  FIG. 3A  illustrating its work principle; 
         FIG. 3D  is a fragmentary, plan view of the lock mechanism of  FIG. 3A  illustrating its work principle; 
         FIG. 3E  is a fragmentary, plan view of the lock mechanism of  FIG. 3A  illustrating its work principle; 
         FIGS. 4A  is a fragmentary sectional view of the master light switch showing the controls and the mode lens; 
         FIGS. 4B  is a fragmentary, elevational view of the master light switch showing the controls and the mode lens; and 
         FIGS. 5A-5F  are fragmentary, perspective views illustrating some alternate embodiments of the master light switch of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
     Referring now to the drawings in detail wherein like reference numerals have been used throughout the various figures to designate like elements, there is shown in FIG.  1 A- 1 FF a master lighting switch (“MLS”)  10  constructed in accordance with the principles of the present invention. 
     FIGS.  1 A and  1 AA illustrate the switch  10  includes a housing  14  having an intermediate flange  15  for mounting the switch  10  to a vehicle dashboard or panel. A pin connector  16  for electrical connection of the switch  10  to the vehicle electrical system extends through a back cover  18  of the housing  14 . The switch  10  includes a main knob assembly  22  and an auxiliary lever assembly  26 . 
     FIG.  1 AB illustrate the front face of the master light switch  10 . The selectable functions: “B.O. DRIVE”, “B.O. MARKER”, “OFF”, “STOP LIGHT” and “SER. DRIVE”, associated with the main knob assembly and the functions: “PARK”, “OFF”, “DIM”, and “PANEL BRT.” associated with the auxiliary lever assembly, are known selectable lighting functions for military vehicles, such as for a HUMVEE military vehicle. 
     FIGS.  1 B- 1 FF illustrate internal parts of the master light switch  10 . The master light switch  10  comprises the following main parts or subassemblies:
         A. a main switch assembly  30 ;   B. an auxiliary switch assembly  34 ;   C. the housing  14  including a frame assembly  38  and the back cover  18 ;   D. a contact board assembly  42 ;   E. a control panel assembly  46 ;   F. an illumination board  50 ;       

     A. The main switch assembly  30  is built on the frame assembly  38  and comprises the following: a main rotor assembly  58 , a main cam hub  60 , a main shaft  64 , and a main coil spring  68 . 
     The main shaft  64  includes a flange  64   a  that is held down by an annular portion  69  of the housing  14  ( FIG. 1C ). 
     The main switch assembly  30 , removed from the frame assembly  38  is shown in FIG.  1 CC. The main cam hub  60  includes a ring  59 , such as a metal ring, having a plurality of arcuate cavities  61  wherein each cavity  61  defines a cam surface  62 . A housing  63 , such as a plastic housing, in the form of a disk  63   a  with an upstanding peripheral wall  63   b , includes an annular shoulder or recess  63   d . The ring  59  fits around the shoulder  63   d  and is adhesively secured to the shoulder  63   d . A central downward directed boss  63   e , such as a plastic boss, is adhesively secured to, or formed with, an underside of the disk  63   a . The shaft  64  includes a disk portion  65  having some spaced lugs  65   a  partially inserted into slots  63   c  in the wall  63   b  of the plastic housing  63 . The lugs  65   a  transmit turning torque between the shaft  64  the housing  63 . The coil spring  68  is captured between the disk portion  65  and the disk  63   a  and urges the main cam hub  60  toward the board  86  ( FIG. 1C ). A pair of screws  67   a ,  67   b , spaced 180° around the disk portion  65  ( FIG. 2D ), are used to movably retain the disk portion  65  to the wall  63   b . The screws  67   a ,  67   b  have an excess length to allow a relative axial displacement, along the direction  70 , between the plastic housing  63  and the disk portion  65 . 
     The main rotor assembly  58  comprises a main rotor  71  and main rotor upper sliding contacts  74 , FIGS.  1 CC,  1 E and  1 EE. Upper contacts  74  are situated below the main rotor  71 . The rotor  71  can be composed of a plastic material for electrical insulation purposes. The rotor  71  includes tapered lugs  81  that are used to fix the contacts  74  to the rotor  71 . The contacts have a U-shape wherein the legs of the U-shape have rectangular openings to receive the lugs  81  in a snap fit fashion. The base of the U-shape includes one or more spherical nubs  74   a  facing the board  86 . Coil springs  82 , located partially within the rotor  71  and located between the rotor  71  and the base of the U-shape contacts  74 , are utilized to push down the contacts  74  to firmly contact the nubs  74   a  to a contacts board  86 . 
     The shaft  64  threadingly receives a top screw  87  to secure the knob base  156  ( FIG. 1C ), and the boss  63   e  threadingly receives a bottom screw  88  to secure the rotor  71 . 
     B. The auxiliary switch assembly  34  is built on the frame assembly  38  and comprises the following: an auxiliary rotor assembly  92 , an auxiliary cam hub  96 , an auxiliary shaft  100 , and an auxiliary spring  104 . 
     The auxiliary shaft  100  includes a flange  100   a  that is held down by an annular portion  105  of the housing  14  ( FIG. 1C ). 
     The auxiliary rotor assembly  92  comprises an auxiliary rotor  108  and auxiliary rotor upper sliding contacts  112 , FIGS.  1 D and  1 DD. Coil springs  116  between the rotor  108  and the contacts  112  are utilized to push down the contacts  112  to the contacts board  86 . 
     The auxiliary switch assembly  34  is constructed substantially identically to the main switch assembly  30  described above and shown in FIG.  1 CC, except that the auxiliary rotor is shown having two contact  112  while the main rotor is shown as having three contacts  74 . 
     Non-sliding contacts with or without the coil springs can be used for both main and auxiliary rotors. 
     C. The housing  14  contains all the parts and subassemblies of the MLS  10 . Top external part of the housing  14  also is a part of the locking mechanism. The locking is effected with help of locking teeth that are located under the main knob. 
     The back cover  18  closes the MLS  10 . The pin electrical connector  16  is located on the back cover and is intended to provide connection between the vehicle wiring harness and the MLS  10 . 
     The frame assembly  38  comprises the following parts: a frame  120 , rollers  124 , brackets  128  fixed to the frame  120  that rotationally hold the rollers  124 , and spacer posts  132   a  ( FIG. 1B ),  132   b  ( FIG. 1B) and 132   c  ( FIG. 4B ) for supporting the illumination board  50  from the frame  120 . The frame  120  includes journal portions  129 ,  130  for guiding sliding movement of the respective bosses  63   e  of the switch assemblies  30 ,  34 . Preferably, three rollers  124  and corresponding brackets  128  are provided for each switch assembly  30 ,  34 , spaced at approximately 120° around an axis of the respective switch assembly. 
     D. The contact board assembly  42  comprises the board  86 , a plurality of contacts  134 , and electrical components including but not limited to a resistor  138  and a circuit breaker  142 , as shown in FIGS.  1 F and  1 FF. The contacts  134  and the components are installed on-board and connected in the electrical circuit and to the connector  16  by any applicable method. 
     As a variation, the electrical contacts can be substituted by the following switches included but not limited: magnetic, semiconductor, or solid state. 
     E. The control panel assembly is built on the top of the MLS housing  14  and comprises the following main parts and subassemblies:
         a. the main knob assembly  22 ;   b. the auxiliary lever assembly  26 ;   c. a mode lens  148 ; and   d. side lenses  152 ,  153 .       

     a. The main knob assembly  22  comprises the following: a main lever or knob  155  having a main knob base  156  and a main knob cover  160 , a main knob lens  164 , a locking pin  168 , and two coil springs  170 . The locking pin  168  is located under the main knob base  156  and can be firmly jointed to, or to be part of, the main knob base  156 . 
     b. The auxiliary lever assembly  26  comprises the following: an auxiliary lever or knob  182  and an auxiliary lens  186 . 
     c. The mode lens  148  has the mode markings shown in FIG.  1 AB on the top to help the operator control the MLS  10 . 
     d. The side lenses  152 ,  153  are arranged to transfer light beams from the light sources to the mode lens  148 . Light emitting diodes are used in the preferred embodiment of the invention but they can be substituted by any other type of the lights source, included but not limited: incandescent, halogen, and xenon. 
     F. The illumination board  50  includes a circuit board  187  that mounts and provides electrical circuits and components for operation of the LED-s. The board  187  is spaced from the frame  120  by the spacer posts  132   a ,  132   b ,  132   c . The spacer posts are screwed to the frame  120  and to the board  187 . 
     Turning to  FIGS. 2A-2F , the main and auxiliary switches work principle is depicted using the auxiliary switch  34  as an example. The main switch work principle is identical to the auxiliary switch work principle. 
     Cam hub  96  is firmly jointed with rotor  108  and cam hub  60  with rotor  71  through the journal portions  129 ,  130  in the frame  120 . The frame  120  is located between the rotors and the cam hubs. These two jointed couples are able to move up and down within some restricted distance as well as rotate around their axis. 
     When an operator rotates either the main knob assembly  22  or the auxiliary lever assembly  26  in their turn they rotate the respective cam assemblies  58 ,  92  by the shafts  64 ,  100 . 
     The cam hubs  96 ,  60  rotate onto and over the rollers  124 , and the respective spring  68 , 104  are compressed. When three cam hub cavities  61  are situated exactly on top of the respective three rollers  124 , the cam hub-rotor couple drops down by resilient force from the respective spring  68 , 104  to the lower position as shown in  FIGS. 2E ,  2 F. Thus the respective rotor comes close to the contact board  86  and the respective upper contacts  74 , 112 , particularly the raised nubs  74   a ,  112   a , touch the lower contacts  134  and provide electrical connectivity between the different parts of the contact board  86 . The contact springs  82 ,  116  ensure that an even contact of the nubs  74   a ,  112   a  is made on the board  86 .  FIGS. 2A ,  2 B depict an initial stage of movement of the switch assembly  34  and  FIGS. 2C ,  2 D depict an intermediate stage of movement of the switch assembly  34 . 
     Use of the rollers  124  lowers the friction forces, and will increase the lifetime of the MLS  10 . Balls or other low frictional bearings or components can substitute for the rollers. 
     Turning to  FIGS. 3A-3E , the locking mechanism that is integrated with the main knob assembly  22  is depicted. 
     The locking mechanism prevents reaching of certain restricted modes without undertaking the additional step of unlocking the mechanism. To unlock the locking mechanism the operator has to pull back the main knob cover  160  in the direction  228  against the urging of the two coil springs  170 .  FIGS. 3A ,  3 B show the cover  160  in its relaxed position by solid lines and its pulled back position by broken lines. 
     As shown in  FIG. 3C , the pin  168  is captured within a restricted zone  231  between adjacent teeth  230 , formed as part of the housing  14 , where rotary movement of the knob is restrained. 
     As shown in  FIG. 3D  once the pin  168  is moved radially outwardly by sliding of the cover  160  as shown dashed in  FIG. 3B , the pin  168  is free to be moved, by rotation of the knob, from the position shown as position  168   a  to position  168   b  to position  168   c , or alternately from position  168   a  to position  168   d  to position  168   e . The pin  168  passes over the restricted zone  231  between the teeth  230 . The main knob can be returned back by rotating the knob, wherein the pin  168  is slipped freely over a slight slope or oblique surface  230   a  of the teeth  230  of the locking mechanism as it is depicted in  FIG. 3E . The pin  168  moves from the illustrated position  168   a  to position  168   b  to position  168   c.    
     Turning to  FIGS. 4A ,  4 B, illumination of the control panel  148 , main knob assembly  22  and auxiliary lever assembly  26  are depicted. 
     As it is illustrated on  FIG. 4A , tips on both main knob assembly  22  and auxiliary lever assembly  26  are illuminated by LED-s  236 ,  238  through lenses  164 ,  186 , respectively. Lenses  164 ,  186  are inserted inside of the main knob assembly  22  and auxiliary lever assembly  26 . 
       FIG. 4B  shows that the mode lens  148  is illuminated by two LED-s  250 ,  252  beaming light through the two lenses  152 ,  153 . The LED/lens pair  250 / 152  is on an opposite side of the switch  10  as the LED/lens pair  252 / 153 , the latter pair shown only partially. 
     Lenses according to the preferred embodiments of the present invention are advantageously composed of transparent or translucent plastic material. 
     Turning to  FIGS. 5A-5F , examples are illustrated of some varieties of the MLS&#39;s Control Panel demonstrating alternate aspects of the invention. 
       FIG. 5A  depicts the preferred embodiment of the switch  10  herein described. 
       FIG. 5B  depicts an alternate embodiment switch  300  that utilizes a push-on main knob  310  to unlock the mechanism. 
       FIG. 5C  depicts an alternate embodiment switch  350  that utilizes push auxiliary buttons  360  instead of the auxiliary lever. 
       FIG. 5D  depicts an alternate embodiment switch  400  that utilizes a separate unlocking push button  410  to unlock the mechanism. The button  410  is located outside of the main knob assembly  420  and it is activated before rotating the main knob assembly  420 . 
       FIG. 5E  depicts an alternate embodiment switch  450  that utilizes a separate unlocking push momentary button  460  to unlock the mechanism. The button is located on the main knob assembly  470 . 
       FIG. 5F  depicts an alternate embodiment switch  500  that utilizes a separate unlocking push momentary button  510  to unlock the mechanism. The button  510  is located on the side of the main knob assembly  530 . 
     In addition to variations depicted on  FIG. 5A-FIG .  5 F the shape, size of the knobs, levers and buttons, as well as their locations on the front panel can be different from those shown on  FIG. 5A-FIG .  5 F to accommodate the MLS design to concrete needs of the production requests, which is in harmony with the present invention. 
     From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred.