Patent Publication Number: US-7224578-B2

Title: Ergonomic control panel for a portable electric generator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation of U.S. patent application Ser. No. 09/873,468 filed on Jun. 4, 2001 now U.S. Pat. No. 6,801,425. The disclosure of the above application is incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention relates to control panels for devices such as portable electric generators, and more particularly to an ergonomic control panel for a portable electric generator. 
   BACKGROUND OF THE INVENTION 
   Portable electric generators are used in a wide variety of applications. Such applications include use at construction sites for powering various electric power tools such as drills, saws, lights, electric heaters, etc., as well as in residential applications for providing a back-up source of electric power in the event of a power outage. Such portable electric generators typically have a control panel with a plurality of electrical outlets and switches for selecting certain outlets thereof for use. For example, generators which provide either 120 VAC or 240 VAC use a switch by which the user selects either 120 VAC or 240 VAC operation. Circuit breakers are also often included at various locations on the control panel. 
   Typically the above-described outlets, breakers and switches are not logically organized on the generator control panel. This can lead to considerable confusion on the part of the user in the event the user is in a hurry to plug a power cord into one of the outlets of the generator or if lighting conditions are not acceptable, leading to difficulty in the operator seeing the switches, outlets or breakers that the user needs to access. 
   Accordingly, it would be highly beneficial to provide a control panel for a portable electric generator that logically groups the various switches, outlets and circuit breakers used to control operation of the generator into different areas or “zones”. More specifically, it would be highly advantageous to provide a plurality of distinct zones on the control panel wherein the various outlets, breakers and switches of the generator are grouped within each zone in a fashion that significantly eases the use of the generator and reduces the possibility of operator error in selecting outlets, switches or breakers. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a control panel for a portable electric generator. The control panel is segmented into a plurality of distinct regions or “zones”. Each zone includes logically related and organized components to minimize the possibility of the operator accidentally selecting the wrong control or mistakingly trying to engage the plug of a power extension cord with an improper (i.e., non-mating) electrical outlet of the generator. 
   In a preferred embodiment, an ON/OFF engine switch is included in the first zone. A plurality of electrical receptacles are included within a second zone disposed adjacent to the first zone. A third zone includes a control for controlling the internal combustion engine of the generator. 
   In one preferred embodiment the first zone also comprises a circuit breaker switch. The circuit breaker switch and the ON/OFF engine switch are further disposed at longitudinally opposite ends of the first zone to reduce the possibility of the operator mistakingly engaging one of these switches when the operator intended to engage the other one of the switches. 
   The second zone includes at least one, and more preferably a plurality, of electrical outlets for supplying a first voltage, and at least one outlet for supplying a second voltage. In one preferred form the first outlets provide 120 VAC and the second outlet provides 240 VAC. The 240 VAC outlet is further disposed at a longitudinally opposite end of the second zone from the first outlets to minimize the possibility of the operator mistakingly trying to plug in a power cord plug into the wrong outlet. The 240 VAC outlet is further separated from the 120 VAC outlets by a voltage selector switch for selecting either 120 VAC or 240 VAC operation. A plurality of thermal circuit breakers are further disposed closely adjacent each of the outlets to provide a clear indication when the current being drawn by a given outlet has exceeded a maximum predetermined level, thus “tripping” the breaker. 
   In the preferred embodiments, each of the zones are further laid out as horizontally disposed, rectangular zones positioned adjacent one another. Optionally, one or more longitudinal frame members of a frame of the generator may be used to demarcate the zones from one another. The frame members also provide protection from accidental damage to electrical components on the control panel. 
   Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawing, wherein: 
       FIG. 1  is a perspective view of a generator incorporating a control panel in accordance with a preferred embodiment of the present invention; 
       FIG. 2  is an enlarged view of just the control panel and a portion of the generator frame; and 
       FIG. 3  is an end view of a portion of the generator. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , there is shown a control panel  10  used with a portable electric generator  12 . The generator  12  includes a frame  14  for supporting an internal combustion engine  16 . An electric generator (hidden from view) is coupled to an output shaft of the engine  16 . 
   Referring to  FIG. 2 , the control panel  10  is shown in greater detail. The control panel  10  includes a plurality of switches and electrical receptacles which are logically and ergonomically arranged to provide significantly increased ease of use of the generator  12 . To this end, the control panel  10  is divided into a plurality of distinct regions or “zones”  18 ,  20  and  22 . The frame  14  further includes tubular frame members  14   a ,  14   b  and  14   c  which are disposed generally parallel to one another, and which further help to demarcate the three distinct zones  18 ,  20  and  22  of the control panel  10  and to protect the components on the control panel from damage due to accidental contact with other tools or objects. Each zone  18 ,  20  and  22  comprises a horizontally laid out, generally rectangular area, and each of the zones are arranged parallel to one another. The uppermost zone  18  includes an ON/OFF engine switch  24  at one longitudinal end of the zone  18  and a main circuit breaker switch  26  at the opposite longitudinal end of the zone. The switches  24  and  26  are further separated by an indicia member or area  28  in which a company name or other indicia identifying the manufacturer of the generator  12  may be included. The first zone  18  of the control panel  10  is further formed so as to be inclined slightly relative to the other zones  20  and  22 , as indicated in  FIG. 3 , to present slightly easier access to the switches  24  and  26 . Each of the switches  24  and  26  are illustrated as rocker style switches, but it will be appreciated that push button switches, slide style switches, toggle style switches or virtually any other form of switch could easily be incorporated in lieu of rocker style switches. 
   The second zone  20  is also configured as an elongated, rectangular region. The second zone  20  includes a plurality of electrical receptacles or outlets  30 ,  32 ,  34  and  36  arranged within a first subregion  20   a . Outlets  30  and  36  comprise conventional twist lock receptacles for use with mating male twist lock electrical plugs. Outlets  30  and  36  preferably are capable of supplying 20 to 30 amps of current. Electrical outlets  32  and  34  are ground fault interrupter (GFI) electrical outlets which each supply 120 VAC and preferably up to 20 amps of current or more. 
   Thermal circuit breakers  38 ,  40 ,  42  and  44  are each associated with a respective one of the outlets  30 – 36 . Advantageously, each thermal breaker  38 – 44  is disposed closely adjacent the electrical receptacle  30 – 36  with which it is associated. Thus, thermal breaker  38  is associated with outlet  30 , thermal breaker  40  is associated with outlet  32 , thermal breaker  42  is associated with outlet  34  and thermal breaker  44  is associated with outlet  36 . 
   With further reference to  FIG. 2 , a voltage selector switch  46  is disposed within a second subregion  20   b  of region  20  while a 120/240 VAC electrical outlet  48  is disposed within a third subzone  20   c  of zone  20 . The voltage selector switch  46  in one preferred from comprises a rocker style switch which is laid out horizontally. Indicia  46   a  to the left of switch  46  indicates to the user that depressing the left side of the switch selects the outlets  30 – 36  for maximum 120 VAC power. Pressing the right side of switch  46  selects outlet  48  for 240 VAC operation. The placement of the switch  46  inbetween the group of outlets  30 – 36  and outlet  48 , along with its horizontal positioning, helps to ensure that the operator realizes which electrical receptacles are being selected for use. By requiring the operator to push the left side of the switch  46  if one or more of the electrical outlets  30 – 36  are to be used, or to depress the right side of the switch  46  if outlet  48  is to be used, there is a further degree of logical control introduced into the selection of which outlets  30 – 36  and  48  the operator is selecting for use. 
   Another advantage to the above-described layout is that the 120/240 VAC electrical outlet  48  is disposed at the longitudinally opposite end of the zone  20   b  from the 120 VAC electrical outlets  30 – 36 . This further helps to reduce the possibility that the operator may inadvertently attempt to plug a 120 VAC electrical plug into the 120/240 VAC outlet  48 . 
   The third zone  22  includes an “Idle Control” on/off switch  52 . This switch is typically used less frequently than switches  24 ,  26  or  46 , and is therefore disposed at the lowermost area of the control panel  10 . Switches  24  and  26 , being much more commonly used, are disposed in the first zone  18 . The auto throttle on/off switch  52  is used to choose whether or not the gas engine  16  will run at one constant speed, or throttle up and throttle down automatically depending on current draw on the generator  12 . 
   From the foregoing, then, it will be appreciated that the control panel  10  of the present invention provides the switches, electrical outlets and circuit breakers typically used with a portable electric generator in a highly logically organized arrangement. The arrangement of the control panel  10  into distinct zones further significantly reduces the possibility of the user unintentionally attempting to engage the wrong electrical outlet with a given electrical plug. The placement of the various control switches also significantly improves the convenience of use of the control panel  10  by locating those switches which are accessed most frequently at the upper area of the control panel, while switches which are accessed less frequently are disposed at lower locations on the control panel. The generally central placement of the voltage selector switch  46  further helps to ensure that the operator will not accidentally select the wrong electrical outlet for use. 
   Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification and following claims.