Patent Abstract:
A switch assembly for a wet/dry vacuum cleaner is disclosed. The switch assembly includes a switch having a movable arm adapted to connect first and second conductive terminals with a rocker arm pivotally attached to the switch. The rocker arm is operable by an actuator button and a de-actuator button which are user engageable. Depending upon which of the de-actuator and actuator buttons are depressed, the rocker arm assumes a given position relative to the switch, which in turn results in an on or off position for the switch. An automatic shut-off assembly is operable in conjunction with the switch assembly to turn the switch to an off position in the event that the level of liquid within the tank rises beyond an acceptable level. The switch assembly enables the operator to manually override the automatic shut-off assembly.

Full Description:
FIELD OF THE INVENTION  
         [0001]    The invention generally relates to wet/dry vacuum cleaners and, more particularly, relates to actuator switches for wet/dry vacuum cleaners having a pumping capability.  
         BACKGROUND OF THE INVENTION  
         [0002]    Wet/dry vacuum cleaners are well-known. Such devices typically include a tank to which a removable lid is attached. A motor driven impeller is typically mounted within the lid to generate low pressure within the tank and thus create a vacuum for drawing matter in solid, liquid, and/or gaseous form therein.  
           [0003]    Once the tank is filled, the user is confronted with the obstacle of emptying the tank, which can be unwieldy and heavy once filled. Conventionally, operators are provided with two options: one, the lid can be removed, and the tank can be tilted to empty its contents; and two, a drain provided at the bottom of the tank can be opened to drain the liquid therefrom. Such a latter option is viable only in the event that a suitable floor drain is provided.  
           [0004]    Recently, certain wet/dry vacuum cleaners have been provided with a pumping capability. Therefore, in addition to being provided with an impeller to draw matter into the tank, a pump having an impeller typically mounted to the same motor shaft as that driving the vacuum impeller, is provided to evacuate or discharge liquid matter from the tank. One example of such a device is disclosed in U.S. Pat. No. 6,009,596 assigned to the present assignee, and expressly incorporated herein by reference.  
           [0005]    With such wet/dry vacuum cleaners which include pumping capability, it is important that the level of liquid within the tank does not rise to the level of the vacuum impeller. Accordingly, such devices are typically provided with an automatic shut-off mechanism which severs power to the motor in the event that the level of liquid in the tank exceeds a safe margin. Upon triggering the automatic shut-off, the operator is then typically provided with an override capability which enables the pump to discharge liquid after the user has manually removed the vacuum intake from the source of liquid or debris.  
         SUMMARY OF THE INVENTION  
         [0006]    In accordance with one aspect of the invention, a wet/dry vacuum cleaner switch assembly is provided which includes a switch, a rocker arm, an actuator, a de-actuator, a float, and a tie rod. The switch has first and second spaced terminals and a spring biased momentary arm. The spring biased momentary arm is adapted to move from an on position connecting the first and second spaced terminals to an off position disconnecting the first and second spaced terminals. The rocker arm is pivotally associated with the switch and includes an engagement surface adapted to move the momentary arm from the off position to the on position. The actuator is operatively associated with the rocker arm and is user engageable to move the rocker arm. The movement of the rocker arm by the actuator causes the engagement surface to move the momentary arm from the off position to the on position. The de-actuator is operatively associated with the rocker arm and is user engageable to move with the rocker arm. Movement of the rocker arm by the de-actuator causes the engagement surface to disengage from the momentary arm, while the engagement of the engagement surface with the momentary arm causes the spring biased momentary arm to move from the on position to the off position. The tie rod is connected between the float and the rocker arm. Upward movement of the float causes the tie rod to pivot the rocker arm which in turn causes the momentary arm to move from the on position to the off position.  
           [0007]    In accordance with another aspect of the invention, a wet/dry vacuum cleaner is provided which comprises a tank, a removable lid, a motor, a vacuum impeller, a pump impeller, a switch assembly, a float, and a tie rod. The tank has an open top with the removable lid being attached to the open top. A motor positioned within the lid includes a shaft extending therefrom. A vacuum impeller and pump impeller are attached to the motor shaft. The switch assembly is connected to the motor and includes a rocker arm. The float is disposed within the tank and the tie rod is connected between the switch assembly and the float.  
           [0008]    In accordance with another aspect of the invention, a wet/dry vacuum cleaner of the type having a tank, a motor, a vacuum impeller connected to the motor, a pump impeller connected to the motor, a switch connected to the motor and a float assembly disposed from the tank and connected to the switch is provided which includes a manual override switch assembly having a rocker arm, an actuator button, and a de-actuator button. The rocker arm is operatively associated with the switch, the switch includes a movable element adapted to open or close the switch. The rocker arm is adapted to move the movable element and includes first and second ends. The actuator button is operatively associated with the rocker arm first end and the de-actuator button is operatively associated with the rocker arm second end.  
           [0009]    In accordance with another aspect of the invention, a wet/dry vacuum cleaner switch assembly is provided which comprises a rocker switch adapted to pivot from an on position to an off position, and a buoyant float connected to the rocker switch and adapted to move the rocker switch from the on position to the off position.  
           [0010]    These and other aspects and features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.  
         BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]    [0011]FIG. 1 is a side view of a wet/dry vacuum cleaner constructed in accordance with the teachings of the invention;  
           [0012]    [0012]FIG. 2 is a sectional, partially cut-away view of a tank, lid, power assembly, float, and switch assembly constructed in accordance with the teachings of the invention;  
           [0013]    [0013]FIG. 3 is a side cut-away view of a lid, power assembly and switch assembly constructed in accordance with the teachings of the invention with the switch assembly shown in an off position;  
           [0014]    [0014]FIG. 4 is a side cut-away view of a lid, power assembly, and switch assembly constructed in accordance with the teachings of the invention with the switch assembly shown in an on position;  
           [0015]    [0015]FIG. 5 is a side cut-away view of a lid, power assembly, and switch assembly constructed in accordance with the teachings of the invention with the switch assembly depicted in automatic shut-off position;  
           [0016]    [0016]FIG. 6 is a side cut-away view of a lid, power assembly, and switch assembly constructed in accordance with the teachings of the invention with the switch assembly shown in an override position;  
           [0017]    [0017]FIG. 7 is a side cut-away view of a lid, power assembly, and switch assembly constructed in accordance with the teachings of the invention with the switch assembly depicted in an on position with actuator and de-actuator buttons biased outwardly to the same height;  
           [0018]    [0018]FIG. 8 is an end view of a switch assembly and an automatic shut-off assembly constructed in accordance with the teachings of the invention; and  
           [0019]    [0019]FIG. 9 is a side view of FIG. 8. 
       
    
    
       [0020]    While the invention is susceptible to various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention as defined by the appended claims.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Referring now to the drawings, and with specific reference to FIG. 1, a wet/dry vacuum cleaner constructed in accordance with the teachings of the invention is generally depicted by reference numeral  20 . While the vacuum cleaner depicted is of a wet/dry vacuum cleaner type, it is to be understood that the switch assembly of the invention can be employed with other types of vacuum cleaners and pumps as well.  
         [0022]    As shown in FIG. 1, the vacuum cleaner  20  includes a tank  22  to which a lid assembly  24  is removably attached. The lid assembly  24  includes a handle  26  to facilitate moving the vacuum cleaner  20  as well as removal of the lid assembly  24 . A plurality of casters or other types of wheels  28  are attached to the tank  22  to also facilitate movement.  
         [0023]    Turning now to FIG. 2, it can be seen that a power assembly  30  is mounted within the lid assembly  24 . More specifically, the power assembly  30  includes a motor  32  from which a rotatable shaft  34  extends. A vacuum impeller  36  is mounted to the shaft  34  with a pump impeller  38  being mounted below the vacuum impeller  36 . Accordingly, upon energization of the motor  32 , both the vacuum impeller  36  and pump impeller  38  rotate with the shaft  34 . The vacuum impeller  36  is mounted for rotation within a shroud  40 . Rotation of the vacuum impeller  36  within the shroud  40  creates a low pressure within the tank  22  thereby drawing matter into the tank  22 .  
         [0024]    The pump impeller  38  is mounted for rotation within a chamber  46 . The chamber  46  includes an inlet  48  and an outlet  50 . An intake tube  52  extends downwardly from the inlet  48  into the tank  22  and terminates in a pump intake assembly  54 .  
         [0025]    In order to energize the motor  32 , a switch assembly  56  is provided. As shown in FIGS.  3 - 7 , the switch assembly  56  includes a switch  58  to which a rocker arm  60  is pivotally attached at a pivot  62 . The switch assembly  56  also includes an actuator button  64  and a de-actuator button  66 . The actuator button  64  is mounted for reciprocating motion proximate a first end  68  of the rocker arm  60 , while the de-actuator button  66  is mounted for reciprocating motion proximate a second end  70  of the rocker arm  60 . The switch assembly  56  also includes an automatic shut-off assembly  72  which includes a float  74  mounted for linear motion within a cage  76  and a tie rod  78  connecting the float  74  to the rocker arm  60 .  
         [0026]    With reference now to FIG. 9, the switch  58  is shown to include a housing  80  from which first and second terminals  82 ,  84  extend. A momentary or movable arm (not shown) is mounted within the switch housing  80  and is adapted to move from a first or on position connecting the terminals  82 ,  84 , to a second or off position disconnecting the terminals  82  and  84 .  20  The movable arm, and first and second terminals  82  and  84  are manufactured of a suitable electrically conductive material, such as copper, such that when the movable arm is in the on position, the terminals  82 ,  84  are connected and a circuit is completed to thereby connect a power cord  88  (FIG. 1) to the motor  32  (FIG. 2) for energization thereof. The movable arm is preferably spring biased into the off position. An actuator tab  90  extends from the movable arm outward through the housing  80  to engage the rocker arm  60  to engage the movable arm  86  as will be described in further detail herein. The switch  58 , in a preferred embodiment, is provided in the form of a Unimax model no. TMCJG6SP0040Y switch manufactured by C &amp; K/Unimax Inc. of Willingford, Conn.  
         [0027]    Referring now to FIG. 8, the rocker arm  60  is illustrated to include a receptacle  94  which receives the tie rod  78 . The receptacle  94  is preferably integrally molded with the rocker arm  60  and extends laterally therefrom. The rocker arm  60  and receptacle  94  are preferably manufactured from a suitable plastic, such as ABS. Extending from a top surface  96  of the first end  68  of the rocker arm  60  is an extension arm  98 , as shown best in FIG. 9. The extension arm  98  serves as an extension enabling contact of the actuator button  64  and the rocker arm  60 , as will now be described.  
         [0028]    As shown in FIGS.  3 - 7 , each of the actuator button  64  and de-actuator button  66  is mounted within a recess  100  molded into the cover  101  of the lid assembly  24 . The recess  100  includes an outer wall  102  and a floor  104 . Each of the actuator button  64  and de-actuator button  66  includes a stem  112  (FIG. 9) extending through the floor  104 . In the preferred embodiment, each of the actuator button  64  and de-actuator button  66  are biased by springs  105  into an extended position away from the floor  104 .  
         [0029]    In operation, the switch assembly  56  and shut-off assembly  72  function to actuate and de-actuate the vacuum motor  32  and thus the vacuum impeller  36  and pump impeller  38 . With reference to FIG. 3, the switch assembly is depicted in an off position with the de-actuator button  66  depressed into the recess  100 . This in turn presses the second end  70  of the rocker arm  60 , which in turn raises the first end  68  of the rocker arm  60 . In so doing, an engagement surface  118  (FIG. 9) extending from the rocker arm  60  pivots away from the actuator tab  90  of the switch  58 . This in turn allows the biased movable arm of the switch  58  to disconnect the terminals  82 ,  84  to thereby open the switch  58  and de-actuate the motor  32 .  
         [0030]    When it is desired to operate the vacuum impeller  36  and/or pump impeller  38 , the actuator button  64  is depressed into the recess  100 , as shown in FIG. 4. This in turn causes the stem  112  of the actuator button  64  to act upon the extension arm  98  of the rocker arm  60 . In turn, the first end  68  of the rocker arm  60  is pivoted downwardly which in turn causes the engagement surface  118  to pivot inwardly and push the actuator tab  90  of the switch  58  inwardly. This in turn causes the movable arm to connect the terminals  82  and  84 , thereby completing a circuit and actuating the motor  32 .  
         [0031]    To facilitate this motion, the engagement surface  118  includes a cam surface  120  and a locking ledge  122  which meet at a juncture  124 , as shown best in FIG. 9. By providing the canted or angled cam surface  120 , the engagement surface  118  is able to slide relative to the actuator tab  90  while pivoting inwardly toward the switch  58  and thereby depressing the actuator tab  90  inwardly. In order to maintain the actuator tab  90  in the inward or on position, the locking ledge  122  is shaped and spaced away from the switch  58  sufficiently to maintain the on position. More specifically, once the juncture  124  of the engagement surface  118  moves past the actuator tab  90 , the locking ledge  122  is provided at a minimal angle to an end  126  of the actuator tab  90  such that the outward biasing force generated by the movable arm is imparted on the angled surface of the locking ledge  122  while tending to pivot the rocker arm  60  in the “on” direction thus providing a minimal force of rotation to hold pivot arm  60  (against a stop) in the “on” position. In order to move the switch assembly  56  from the on position depicted in FIG. 4, the user either needs to manually depress the de-actuator button  66  to the position shown in FIG. 3, or the automatic shut-off assembly  72  needs to operate to force the switch assembly  56  into the position depicted in FIG. 5.  
         [0032]    Operation of the automatic shut-off assembly  72  is as shown in FIG. 5, wherein the first end  68  of the rocker arm  60  has pivoted upwardly. Such upward movement of the rocker arm  60  and first end  68  causes the engagement surface  118  to move out of contact with the actuator tab  90 , which in turn moves the movable arm  86  out of contact with the terminals  82  and  84 , thereby de-activating the motor  32 . The force causing the upward movement of the first end  68  of rocker arm  60  is generated by the float  74 , which in turn is imparted to the rocker arm  60  by the tie rod  78 . As shown in FIG. 5, when the amount of liquid within the tank  22  rises so as to contact the float  74 , the float  74  can rise within the cage  76  with the rising liquid. The upward buoyant force generated by the float  74  is sufficiently stronger than the frictional and rotational force generated between the locking ledge  122  and actuator tab  90  to thereby force the first end  68  of the rocker arm  60  upwardly.  
         [0033]    Even after the automatic shut-off assembly  72  has functioned to de-energize the motor  32  and thereby prevent further liquid from being brought into the tank  22 , the motor  32  can again be energized if the user so desires. Before doing so, the user would typically remove the vacuum hose (not shown) from the source of liquid being vacuumed. Accordingly, once the motor  32  is energized, even though the vacuum impeller  32  is rotating, only the pump impeller  38  would actually be drawing fluid therethrough to thereby lower the level of liquid within the tank  22 .  
         [0034]    In order to manually override the automatic shut-off assembly  72 , the user simply depresses the actuator button  64  with sufficient force to overcome the buoyant force generated by the float  74 . The operator is required to continually depress the actuator button  64  , otherwise the buoyant force of the float  74  again returns the switch assembly  56  to the shut-off position depicted in FIG. 5, at least until the level of fluid within the tank has dropped below the level of the float  74 . This override position is depicted in FIG. 6. Once the level of liquid within the tank  22  has dropped below the float  74 , the float  74  rests upon the bottom of the cage  76  with the tie rod  78  positioned without contact with the rocker arm  60 . This allows the switch assembly  56  to remain in the “on” position when actuator button  64  is released (FIG. 7). As shown therein, the stems  112  of the actuator and de-actuator buttons  64  and  66  rest above their respective contact portions of the rocker arm  60 . This can be accomplished by biasing the buttons  64 ,  66  upwardly by the springs  105 , and does not apply undesirable influence to rocker arm  60  during operation. The actuator button  64  and the de-actuator button  66  are thereby caused to be equidistantly raised within the recess  100 . The operator can then reposition the vacuum hose for both vacuum and pumping operation.  
         [0035]    From the foregoing, it can be appreciated by one of skill in the art that the invention provides a switch assembly for a wet/dry vacuum cleaner having vacuum and pumping capability, with an automatic shut-off and manual override capability as well.

Technology Classification (CPC): 0